African Marijuana SeedsAfrican Marijuana Seeds
African Marijuana Seeds
 Marijuana seeds

Cannabis seeds

Water Bongs

Glass pipes
 In this section we want to show You how easy growing marijuana is.
This grow guide is dedicated for both, a beginner and a moderate grower. In parenthesis, every marijuana lover can find something useful here.
Choosing a Site
Where to Grow

Types of Soil
Humus and Composts
Techniques for Preparing Soils
Guerrilla Farming

Planting and Transplanting
When to Plant
Preparing to Sow

Caring for the Growing Plants
Gardening Tips

Insects and Other Pests
Biological Control
Chemical Insecticides
Common Pests
Vertebrate Pests





African Marijuana Seeds
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There are several factors to consider when deciding where to plant, including sunlight, microclimate, availability of water, and condition of the soil. But the garden's security should be your first consideration. No matter what size your garden, rip-offs and confiscation are constant threats. But these risks can be minimized by careful planning and common senses.

In some countries, law-enforcement agencies take a tolerant attitude toward small gardens, and people grow Cannabis in their backyards. In other areas, police are not as enlightened and place an emphasis on cultivation busts. In either case, the larger the garden, the greater the potential danger. (Figure 55. A Nassau Country police officer stands in a field of marijuana plants in Lattingtown, Long Island.)

In Hawaii and California, where marijuana growing has become a booming business, helicopters have been a problem for commercial growers. Aircraft outfitted with visual or infrared equipment, dogs, and finks have all been used to seek out illicit plots. Aircraft equipment is least effective on steep slopes and where the vegetation is lush and varied. Where aircraft are a problem, growers prune marijuana to obscure its distinctive shape. The plants are difficult to detect from a distance when intercropped with bamboo, sunflowers, sugar cane, soybeans, or tall weeds (see Figure 60). Commercial growers often plant several small dispersed stands or many single plants, which are more difficult to detect and serve as insurance against total loss.

But rip-offs rather than the law are more of a problem for marijuana growers. From every section of the United States, reports confirm that marijuana theft has reached epidemic proportions, and even well-hidden plant fall prey to unscrupulous people. These lowlifes often search near hippie communities and popular planting areas. Their best ally is a loose lip; so keep your garden on a "need to know" basis.

1.2 Where to Grow

Given the value of marijuana, many people think they'll grow an acre or two. But it is much harder to find spots suitable for large-scale farming than to find small garden plots. Large gardens require more planning and commitment, and usually a remote area. They may need a lot more time, energy, and investment in materials and labor-saving machinery than smaller gardens.

A small but well-cultivated garden, say, ten by ten feet, can yield over four pounds of grass each crop. By planning realistically, you'll harvest a good stash of potent grass rather than a lot of disappointment.

Moat people who grow marijuana plant it in their backyards. They hide the plants from curious neighbors and passers-by with walls, fences, arbor, or similar enclosures. Some people plant Cannabis as part of their vegetables garden, pruning the plants to make them less conspicuous.

Gardeners often use ingenious ideas to keep their gardens secret. A woman on Long Island grows over thirty large plants in containers in her drained swimming pool. Although some of the plants reach a height of 12 feet, they can't be seen over the enclosing fence.

A couple living near Nashville, Tennessee, took the roof off their three-car garage and painted the walls white to create a high-walled garden. Other growers use sheds with translucent roofs.

guerrilla Farming

Many growers feel safer planting away from their property. Should the garden be discovered, they are not in jeopardy. On the negative side, they usually lose the close contact and control that a home gardener has.

Urban gardeners use makeshift greenhouses, rooftops, vacant lots, and city dumps. Vacant lost that are overgrown with lush weeds can support a good crop, if the marijuana plants get a head start on the indigenous weeds.

Fields, forest clearings, railroad rights-of-way, stream banks, runoff and irrigation ditches, clearings beneath high-tension lines, deserted farms and quarries, overgrown fields, and abandoned houses have all been used as garden spots. In areas where hemp is a problem weed, people plant seeds from high-potency marijuana in the same fields where the weedy hemp grows. Growers harvest the plants in late July before they flower and before the fields are watched or destroyed by law enforcers.

Larger growers often look for rough, unpopulated terrain that is accessible only by plane, helicopter, four-wheel-drive vehicles, or long hikes. They avoid areas which hunters and hikers are likely to use before harvest.

Serious growers often find unusual places to start gardens. A grow in Chico, California, hacks through two hundred yards of dense underbrush and bramble to reach his clearing. In Oregon some growers maintain fields which are a grueling eight-hour uphill hike from the nearest road. Some Florida farmers commute to their island and peninsula gardens by boats. A master gardener in Colorado lowers himself by rope to a fertile plain 50 feet below a cliff.

A farmer in Hawaii wrote, "The main concern is to grow in an undetectable place where the plants can still get enough sun. This is becoming very difficult to find and some very elaborate subterfuges have been developed. People on Maui are growing plants suspended from trees and on tree platforms! Around here some people carry small plants in buckets far out on the lava fields where there is a light shading from Ohia trees and you don't leave tracks. Also people go into the sugarcane fields, tear out some cane, and put in their plants. I am sure many other things are being done."

1.3 Light

Marijuana is a sun plant. The plants will grow in partially shaded areas, but about five hours of direct sunlight are needed for development into a lush bush. Marijuana does best when it has direct sunlight all day. If it grows at all in a heavily shaded area, it will be dwarfed and sparse - a shadow of its potential.

Try to choose a place that maximizes light. Flat areas get the most sunlight, but many growers prefer to use slops and hillsides which help to hide the plants. Southern slops usually receive more sun and stronger light than eastern and western slops, which are shaded in the afternoon and morning, respectively. Northern slopes are rarely used, since they get the least sunlight and are also the coldest. Steeper slops are shaded sooner than gradual slopes, and lower areas are shaded earlier than high ones.

Sunlight at high altitudes is more intense, because of the thinner atmosphere and the usually lower pollution. The atmosphere and pollutants at lower elevations absorb and scatter some of the solar radiation.

Backyard gardeners usually compromise between the need for maximum light and the need for subterfuge. An area that gets several hours of direct sunlight and bright unobstructed daylight for the rest of the day will do well. A garden exposed to the south usually gets the strongest light and is the warmest. Overhanging vegetation should be pruned so that the plants are shaded as little as possible.

Most marijuana strains are acclimated to tropical and semitropical latitudes, where the daytime is relatively short (10 to 14 hours, depending on season), but the sunlight is quite strong. At latitudes in the United States, the sun is not as intense (although in the summer the difference is small), but the days are longer, and the plants can grow extremely fast. It is not true that intense sunlight is needed to grow great marijuana. However, a summer characterized by clear sunny weather will usually produce a larger and slightly more potent crop than if the season is cloudy and rainy.

Sunlight can be maximized by adequate spacing and orientation of the garden. This is covered in section 11.


Of all the factors involved in growing plants, soil is the most complex. It has its own ecology, which can be modified, enriched, or destroyed; the treatment it receives can ensure crop success or failure.

There is no such thing as the perfect soil for Cannabis. Each variety can grow within a wide range of soil conditions. Your goal is garden soil within the range for healthy growth: well-drained, high in available nutrients, and with a near neutral (7.0) pH. Cannabis grows poorly, if at all, in soils which are extremely compacted, have poor drainage, and low in fertility, or have an extreme pH.

There are several soil factors that are important to a grower; these include soil type, texture, pH, and nutrient content. We will begin this chapter by discussing each of these topics in succession, and will then turn to discussion of fertilizers, soil-preparation techniques, and guerrilla farming methods.

2.2 Types of Soil

Each soil has its own unique properties. These properties determine how the soil and plants will interact. For our purposes, all soils can be classified as sands, silts, clays, mucks, and loams. Actually, soils are usually a combination of these ingredients. If you look carefully at a handful of soil, you may notice sand granules, pieces of organic matter, bits of clay, and fine silty material.

Sandy Soils

Sands are formed from ground or weathered rocks such as limestone, quartz, granite, and shale. Sandy soils may drain too well. Consequently, they may have trouble holding moisture and nutrients, which leach away with heavy rain or watering. Some sandy soils are fertile because they contain significant amounts (up to two percent of organic matter, which also aids their water-holding capacity. Sandy soils are rich in potassium (K), magnesium (Mg), and trace elements, but are often too low in phosphorous (P) and especially nitrogen (N). N, which is the most soluble of the elements, is quickly leached from sandy soil. Vegetation on sands which is pale, yellowed, stunted, or scrawny indicates low nutrients, usually low N.

Sandy soils can be prepared for cultivation without much trouble. They must be cleared of ground cover and treated with humus, manure, or other N-containing fertilizers. In dry areas, or areas with a low water table, organic matter may be worked into the soil to increase water-holding capacity as well as fertility. Sandy soil does not usually have to be turned or tilled. Roots can penetrate it easily, and only the planting row need be hoed immediately before planting. Growers can fertilize with water-soluble mixes and treat sandy soil almost like a hydroponic medium.

Sandy soils are also good candidates for a system of sheet composting (spreading layers of uncomposted vegetative matter over the garden), which allows nutrients to gradually leach into the soil layers. Sheet composting also prevents evaporation of soil water, since it functions as a mulch.


Silts are soils composed of minerals (usually quartz) and fine organic particles. To the casual eye, they look like a mucky clay when wet, and resemble dark sand or brittle clods when dry. They are the result of alluvial flooding, that is, are deposits from flooding rivers and lakes. Alluvial soils are usually found in the Midwest, in valleys, and along river plains. The Mississippi Delta is a fertile alluvial plain.

Silts hold moisture but drain well, are easy to work when moist, and are considered among the most fertile soils. They are frequently irrigated to extend the length of the growing season. Unless they have been depleted by faulty farming techniques, silts are rich in most nutrients. They often support healthy, vigorous vegetation. This indicates a good supply of N.


Mucks are formed in areas with ample rainfall which supports dense vegetation. They are often very fertile, but may be quite acidic. They usually contain little potassium.

Mucks range from very dense to light sandy soils. The denser ones may need heavy tilling to ensure healthy root development, but the lighter ones may be cleared and planted in mounds. Mucks can support dense vegetation, and are often turned over so that the weeds thus destroyed form a green manure.

Clay Soils

Clays are composed of fine crystalline particles which have been formed by chemical reactions between minerals. Clays are sticky when wet, and can be molded or shaped. When dry, they form hard clods or a pattern of square cracks along the surface of the ground. Clays are usually hard to work and drain poorly. Marijuana roots have a hard time penetrating clay soils unless these soils are well-tilled to loosen them up. Additions of perlite, sand, compost, gypsum, manure, and fresh clippings help to keep the soil loose. Clay soils in low-lying areas, such as stream banks, may retain too much water, which will make the plants susceptible to root and stem rots. To prevent this, some growers construct mounds about six inches to one foot high, so that the stems and tap roots remain relatively dry.

Clay soils are often very fertile. How well marijuana does in clay soils usually depends on how well these soils drain. In certain areas "clay" soils regularly support corn cotton. This type of soil will support a good crop of marijuana. Red color in clay soil (red dirt) indicates good aeration and a "loose" soil that drains well. Blue or gray clays have poor aeration and must be loosened in order to support healthy growth.

A typical schedule for preparing a heavy clay soil In the late fall, before frost, turn soil, adding fresh soil conditioners, such as leaves, grass clippings, fresh manure, or tankage. Gypsum may also be added to loosen the soil. Spread a ground cover, such as clover, vetch, or rye. In early spring, making sure to break up the large clods, and add composts and sand if needed. At planting time, till with a hoe where the seeds are to be planted.

As the composts and green manure raise the organic level in the soil, it becomes less dense. Each year, the soil is easier to work and easier for the roots to penetrate. After a few years, you may find that you only need to turn under the cover crop. No other tilling will be needed.


Loams are a combination of about 40 percent each of sand and silt, and about 20 percent clay. Organic loams have at least 20 percent organic matter. In actuality, a soil is almost always a combination of these components, and is described in terms of that combination, e.g., sandy silt, silty clay, sandy clay, or organic silty clay. Loams range from easily worked fertile soils to densely packed sod. Loams with large amounts of organic matter can support a good marijuana crop with little modification.

2.3 Humus and Composts

Humus and composts are composed of decayed organic matter, such as plants, animal droppings, and microbes. Their nutrient contents vary according to their original ingredients, but they most certainly contain fungi and other microorganisms, insects, worms, and other life forms essential for the full conversion of nutrients. As part of their life processes, these organisms take insoluble chemicals and convert them to soluble forms, which plant roots can then absorb. Humus and composts hold water well and are often added to condition the soil. This conditioning results from the aerating properties and water-holding capacity of humus and composts, as well as balanced fertility.

Humus and composts have a rich, earthy small, look dark brown to black, and may contain partially decayed matter, such as twigs or leaves. They are produced naturally as part of the soil's life process or can be "manufactured" at the site by gathering native vegetation into piles. Composts cure in one to three months, depending on both ingredients and conditions. Decomposition can be speeded up by turning and adding substances high in N. Composts are frequently acidic and are sweetened with lime when they are piled. This also shortens curing time, since the desirable microbes prefer a neutral medium.

2.4 Texture

Soil texture refers to density, particle size, and stickiness, all of which affect the soil's drainage and water-holding characteristics. The most important quality of the soil for marijuana is that it drains well - that is, water does not stand in pools after a rain, and the soil is not constantly wet. In a well-drained soil, the roots are in contact with air as well as water.

Cannabis does best on medium-textured soils: soils that drain well, but can hold adequate water. Loams, silts, and sands usually drain well and are loose enough to permit good root development. Some clays and most mucks are too compact to permit the lateral roots to penetrate and grow. In addition, they often drain poorly, and when dry they may form hard crusts or clods, a condition marijuana cannot tolerate.

Several simple tests will indicate the consistency and drainage qualities of your soil. Test when the soil is moist but not wet. First, dig a hole three feet deep to check the soil profile. In a typical non-desert soil, you will find a layer of decaying matter on the surface, which evolves into a layer of topsoil. Most of the nutrients available to the plant are found at this level or are leached down from it. The topsoil layer is usually the darkest. It may only be an inch thick or may extend several feet. When in good condition, the topsoil is filled with life. Healthy topsoil contains abundant worms, bugs, and other little animals, and is interlaced with roots. If you can easily penetrate the underlying topsoil with your hands, its texture is light enough for healthy root growth.

The next layer, or subsoil, may be composed of a combination os sand, clay, and small rocks, or you may hit bedrock. Sandy, rocky, and loamy subsoils present no problems as long as the topsoil is at least six inches thick. Clay or bedrock often indicates drainage problems, especially if the spot has a high water table and stays wet.

Next scrape up a handful of soil from each layer. Press each handful in your fist, release it, and poke the clump with a finger. If it breaks apart easily, it is sandy or loamy. Clods that stick together, dent, or feel sticky indicate clay or muck.

To test for drainage, fill the hole with water. Wait half an hour to let the moisture penetrate the surrounding soil; then fill the hole with water again. If the water drains right through, you are working with sandy soil. If it doesn't drain completely within 24 hours, the soil has poor drainage.

2.5 pH

The pH is a measure of how alkaline (bitter) or acid (sour) the soil is. The pH balance affects the solubility of nutrients, and helps the plant regulate metabolism and nutrient uptake. The scale for measuring pH runs from 0 to 14, with 7 assigned as neutral. A pH below 7 is acid; a pH above 7 is alkaline.

Marijuana grows in soils with a pH range from 5 to 8.5, but it thrives in nearly neutral soils. Relative to other field crops, it has high lime requirements, similar to those for red or white clover or sunflower. But it does well in fields where plants with medium lime requirements, such as corn, wheat, and peanuts, are grown.

The solubility of nutrients is affected by soil type as well as by the pH. In soils with a high content of organic matter, all nutrients are soluble between 5.0 and 6.5. Phosphorous, manganese, and boron are less soluble at pH values above 6.5. Acid soils are usually found in the United States east of the 100th meridian and along parts of the West Coast, and a deep topsoil layer. Marijuana does best in acid soils when the pH is adjusted to a range of 6.3 to 7.0. (Figure 58. Map of pH for US.)

Mineral soils in the dry western states may be slightly acid to highly alkaline. Most nutrients are very soluble in these soils, as long as the pH ranges from 6.0 to 7.5. Some of these soils are too alkaline (over 8.5); so their pH must be adjusted to near neutral to ensure healthy growth.

Adjusting the pH

First test the soil pH in the garden area. Previous gardeners may have adjusted native soils, or your yard soil may have been trucked in to cover poor native soils, so that the pH of your garden soil may be different from that of other soils in the area. Different soils vary in the amount of material needed to adjust the pH. Sandy soils do not require as much as loam, and loam requires less than clays, partly because of the chemistry, and partly because of the density and physical qualities of the soils' particles.

Adjusting Acid Soils

Acidic soils are treated with limestone, which is expressed as an equivalent of calcium carbonate (CaCO3). Limestone is usually quarried and powdered, contains large amounts of trace elements, and comes in different chemical forms: ground limestone, quicklime, and hydrated lime (which is the fastest acting form). Dolomitic limestone is high in magnesium and is often used to adjust magnesium-deficient soils, such as those found in New England. Marl (ground seashells) is also mostly lime and is used to raise soil pH. Eggshells are another source of lime. They should be powdered as finely as possible, but even so, they take a long time to affect the soil. Wood ashes are alkaline and very soluble; so they have an almost immediate effect.

Every commercial lime has a calcium carbonate equivalent or neutralizing power which is listed on the package. To find out how much to use, divide the total amount of limestone required by the pH test (see Figure 59) by the calcium carbonate equivalent. For instance, a field requires fifty pounds of limestone, but the calcic limestone you are using has an equivalent of 1.78. Divide the 50 by 1.78. The resulting figure, about 29 pounds, is the amount required. Commercial limes also list the grade or particle size of the powder. In order of fineness they are: superfine, pulverized, agricultural grade, and fine meal. The finer the grade, the faster the action. (Figure 59. Approximate amount of lime required to adjust pH of a 7" layer of different types of soil.)

For best results, lime should be added at least four or five months before planting. In this way, the lime has a chance to react with the soil. But acid soils can be limed profitably and time before planting, or after, as long as the lime does not come into direct contact with the plants. Most growers add lime at the same time that they fertilize and turn the soil. That way, tilling and conditioning are handled in one operation. The lime should be worked into the soil to a depth of ten inches. Lime can also be added by spreading it before a rain. Make sure that the soil is moist enough to absorb the rain, so that the lime does not run off. Growers who have not adjusted the pH can dissolve lime in water before they irrigate. However, this is not advised if the water runs through a hose or pump, because mineral buildup may occur in the equipment.

Adjusting Alkaline Soils

Most alkaline soils have a pH no higher than 7.5, which is within the range for optimum growth. Soils that are too alkaline can be adjusted by adding gypsum, which frees insoluble salts, and include iron, magnesium, and aluminium sulphate. Marijuana has a low tolerance for aluminium; so marijuana growers should use iron or magnesium sulphate in preference to aluminium sulphate. sulfur and gypsum are worked into the soil in the same manner as lime.

Some growers correct alkaline soils by adding an organic mulch or by working acidic material into the soil. Cottonseed meal, which is acidic and high in nitrogen, can also be used. As it breaks down, cottonseed meal neutralizes the soil. Pine needles, citrus rinds, and coffee grounds are all very acidic, and can be used to correct alkaline conditions. The addition of soluble nitrogen fertilizers aids the breakdown of these low-nitrogen additives. (See Table 22 in the section on "fertilizers" in this section.)

Adjusting Alkali Soils

Alkali soils (pH usually above 8.5) are hardpacked and crusty, and sometimes have an accumulation of white powdery salts at the surface. They may not absorb water easily and can be extremely difficult to work. To prepare alkali soils with a permeable subsurface for cultivation, farmers leach them of their toxic accumulation of salts. The soils is thoroughly moistened so that it absorbs water. Then it is flooded so that the salts travel downward out of contact with the roots. Gypsum can be added to free some of the salts so that they leach out more easily. Gypsum can be added at the rate of 75 lbs per 100 sq.ft., or 18 tons per acre. Leaching requires enormous quantities of water, an efficient irrigation system, and several months.

(Plate 1. Skylights are a good source of bright, unobstructed light. Thai plant (closest) and Colombian plants reached over 14 feet in six months.

Plate 2. Top: A hidden garden using fluorescent light, foil reflectors, and bag containers. Plants are ten weeks old. Bottom: Simple to construct dome greenhouse in southern California. At two months, some of these plants are six feet tall.

Plate 3. Upper left: Stem of a female plant. Upper right: In full sunlight, a pruned plant can grow incredibly dense. Bottom: A garden in the wilds of Oregon mountains.

Plate 4. Marijuana does well in most gardens. Top: Here a female plant is in early bloom at five months. The main stem was clipped at three months (Berkeley). Middle: Lower branches are spread out to catch the sun. Bottom: A female bud about two weeks before harvest. Leaves show some damage from leafhoppers (insects shown).

Plate 5. A giant sinsemilla cola grown from Mexican seed in northern California.

Plate 6. Top: Purple colors often appear late in life, when vigor is waning. Lower left: Resin glands glistening on a purple, female flowering shoot. Lower right: Yellow male flowers and purple leaves against a normal green leaf.

Plate 7. Top: Male flowers at different stages in development. A line of resin glands can be seen on the anthers of the open flowers. Lower left: Resin glands lining the pollen slit of an anther (x40). Middle right: Male flowers in full bloom. The leaves are covered with fallen pollen. Lower right: Gland heads may fall with the pollen grains. Mature grains are spherical in field of focus (x40).

Plate 8. Top: Resin glands on the lower (adaxial) surface of a small, fresh leaf blade. Integrals are one millimeter (x16). Middle and lower left: Stalked glands are concentrated along the veins of the lower leaf surface (x40). Lower right (x100).

Plate 9. Top: Upper (adaxial) fresh leaf surface. Left of picture, from left to right: Sharp-pointed cystolith hair, stalked gland, and tiny bulbous gland (x40). Lower left: Upper surface of a Thai leaf (x16). Lower right: Upper surface of fresh homegrown Colombian leaf (x40).

Plate 10. A young female flower (homegrown Colombian). Resin glands are not yet fully developed (x16).

Plate 11. Top left: A mature female flower from the same plant is in Plate 10. The flower bract is swollen from the ripe seed it contains. Notice the well-developed resin glands (x25). Top right: A mixture of seeds from common marijuana varieties shows comparative size. Bottom: The tip of a sinsemilla flower at harvest. Notice cream-colored stigmas to the left and the fresh, clear resin glands (x40).

Plate 12. Upper and lower left: An overly ripe sinsemilla flower bract. Many gland heads are brown or missing (top, x16; bottom, x40). Upper and lower right: Carefully handled Thai weed with intact glands. Notice the high concentration of glands and very long stalks on this bract (top, x16; bottom, x40).

Plate 13. Upper and lower left: A Colombian Gold. Gland contents are brown and stalks have deteriorated on this bract (top, x16; bottom, x40). Top right: Hawaiian; well-handled and showing little deterioration (bract x40). Middle right: Gland heads easily detach from stalks when overripe (leaf vein x40). Lower right: Stalked glands on both upper and lower leaf surfaces beginning to brown (leaf margin x40).

Plate 14. Top: Whitefly larvae and their honeydew excretions on the lower surface of a leaf. Middle left: Leaf showing whitefly damage and a tiny adult. Lower left: White speckles on leaves indicating mite damage. Lower right: An overdose, or overuse of pesticide, can kill the plant.

Plate 15. Upper left: Healthy green plant next to a N-deficient plant. Middle left: Ultraviolet burn. Plant was moved outdoors without conditioning. Lower left: "Bonsai" marijuana grown from a cutting. Upper right: Mg-deficient plant has chlorotic leaves dying from their tips. Lower right: Afghani variety, with characteristically wide leaf blades, show minor symptoms of N deficiency (pale leaves and red petioles).

Plate 16. Upper left: Male flowers lose some green and turn "blond" during slow drying. Upper right: Cigar joints made with undried marijuana, which is wrapped with lone blades of fan leaves before drying. Bottom: Sequence shows change in color in one day from sun curing.(Unfortunately, all the plates are in black and white.)

Another method of reclaiming alkali soils is by adding a thick mulch and letting it interact with the soil during the winter. The mulch should be about nine inches thick, or 130 lbs or more per 100 sq.ft. This thick layer neutralizes the salts and also helps to retain moisture.


Marijuana is a high-energy plant which grows quickly to its full potential in a fertile soil that is rich in available nutrients. Nutrients are found in the soil's parent materials: sand, clay, humus, minerals, rocks, and water. Nutrients dissolve in soil water (soil solution), which is then absorbed by the plant. In complex chemical processes, roots release ions in exchange for nutrients that are dissolved in the soil solution.

The soil acts as a reservoir for the nutrients. Most of them are in non-exchangeable forms: that is, they do not dissolve, or dissolve only slightly in water. Only a small percentage of the total reserve is free at any time as the result of chemical processes or microbial action. Healthy soils maintain a balance between free and unavailable nutrients, so that the plants they support continually receive the right amounts of required nutrients. Alkali soils have large supplies of compounds which are extremely soluble. The solution is so concentrated that alkali soils are often toxic to plants.

There are three primary nutrients, N (nitrogen), P (phosphorus), and K (potassium). These are the nutrients that gardeners are most likely to be concerned with and which most fertilizers supply. Soils are most likely to be deficient in one of these nutrients, especially N.

In addition to the primary nutrients, soil supplies plants with three secondary nutrients, Ca (calcium), Mg (magnesium), and S (sulfur), and seven micronutrients: iron, boron, chlorine, manganese, copper, zinc, and molybdenum. Although deficiencies of all the secondary and micronutrients are reported from various parts of the United States, serious deficiencies do not occur often. ((For a discussion of the symptoms of nutrient deficiencies is marijuana, see section 9.))

Marijuana absorbs nutrients primarily through a fine network of lateral roots which grow from the taproot. Lateral roots may spread over an area with a diameter of five feet, and may go as deep as the roots can penetrate. Plants in deep sandy soils or in soils that have porous mineral subsoils may grow roots as deep as even seven feet. Roots which can absorb nutrients from a larger area are more likely to fulfill the plants' needs than are shallow roots which result in shallow topsoil layers over compacted subsoils. When the roots have a large area from which to absorb nutrients, the soil does not need to be as fertile as when the roots are restricted to a small area by poor soil or by being grown in pots.

You can get a good indication of soil fertility by observing the vegetation that the soil supports. If the vegetation is varied, has a lush look to it, is deep green, and looks vigorous, it is probably well-supplied with nutrients. If the plants look pale, yellowed, spindly, weak, or generally unhealthy, the soil is probably deficient in one or more nutrients.


Agricultural colleges, County Extension Agents, and private companies perform soil analyses for a small fee from a sample you mail to them. The tests include nutrient, pH, and texture analyses, and are very accurate. There are also simple-to-use test kits available at nurseries and garden shops which give a fair indication of soil fertility and pH. Test results include a suggested fertilizer and lime program catered to the soil's individual requirements for the crop to be planted. Marijuana has nutrient requirements similar to those for corn, wheat, and sugarcane, and prefers just a little more lime (a more alkaline soil) than those crops; so soil can be fertilized as it would be for those crops.

Soil tests are one indication of soil fertility. They test for available nutrients, but not for reserves that are held in the soil. Test results may also vary because of recent rainfall, changes of moisture content, and seasonal changes. Most soil tests do not measure the ability of the soil to make nutrients available. This is a very important factor when considering a fertilizer program and should not be overlooked. As an example, an uncultivated field showed only moderate amounts of N available, and indicated a need for N fertilizer. The vegetation - tall grass, weeds, and bush - had a healthy look and was dark green, and the lower leaves remained healthy. Obviously, the soil was able to supply an adequate amount of N to the plants, which withdrew it from the soil solution as it became available. The soil and plants had reached a balance, and the soil solution slowly became more dilute over the course of the season.

To a great extent, the soil's ability to maintain a constant and adequate supply of nutrients depends on the soil's humus content. Humus can support dense populations of microorganisms. As part of their life processes, microorganisms decompose organic matter in the humus. Nutrients contained in the organic matter are released by microbes as simply inorganic molecules (e.g., NO3) which can dissolve in soil water. Generally, soils with a high humus content can keep plants supplied with more nutrients than soil tests indicate.

The Primary Nutrients

If you look at any fertilizer package, you will note three numbers on the package. They stand for N-P-K, always in that order. Marijuana does best in a soil which supplies high amounts of N and medium amounts of P and K.


The availability of N is the factor most likely to limit the growth of marijuana. For fast healthy growth, marijuana requires a soil rich in available N. Nitrogen is constantly being replaced in the soil solution by microbial breakdown of organic matter. Some microorganisms can use N directly from the atmosphere. They release N as waste in the form NO3, which is the primary form in which plants absorb N. A small amount of N is also dissolved in falling rainwater. When the soil is moist, it loses N through leaching and to plants. In its available form (NO3, NO2, NH4), N is very soluble and may be carried away with runoff or may drain into the subsoil.

Probably the most accurate method of measuring a soil's ability to produce N is by the percentage of organic matter in the soil (see Table 20). Organic matter releases N at a rate that is determined by the type of soil, the temperature, and the moisture. Generally, the more aerated and warmer the soil, the faster organic matter decomposes and releases N. Most professional testing services report the percentage of organic matter, and some sophisticated kits can also test for it.

In its available state, N is tested in two compounds, ammonium (NH4) and nitrate (NO3). Test results are converted into PPM (parts per million) of N and then added to arrive at the total amount of N available in the soil. The formulas to convert nitrate and ammonium to N are (NO3) * 0.226 = N, (NH4) * 0.78 = N. Each PPM indicates 10.7 pounds of N per acre available in the top 7.87 inches. If the soil level is deeper, there is probably more N available. If it is shallower, less is available. But a test for available N gives only a fair approximation of the soil's ability to feed the plant. An individual test may be untypical because of recent leaching or depletion during the growing season.

An intensively cultivated crop of hemp takes about 250 pounds of N per acre or six pounds per 1,000 square feet from the soil during the growing season. When the plants are spaced well apart, the crop does not require as much N.

Fields which have more than 200 lbs of available N per acre (or 4.5 lbs per 1,000 sq.ft.) at the start of the growing season require no additional fertilization. Soils with less available N will probably yield a larger crop if they are given additional N. Actually, the amount of N that can profitably be used depends on the soil and its potential to produce N as well as on other factors: how fast N is lost, the soil depth, and moisture content.

One way to calculate the amount of N to add to the soil is to build your soil to an "ideal" level. For example, an Iowa silt loam may test about 1.6 pounds of N per 1,000 sq.ft. and an organic content of 3 percent. Together, the available and potential N total about 3.2 lbs per 1,000 sq.ft. To increase the available N to 4.5 per 1,000 sp.ft., you would need to add 1.3 lbs of N.


P is an important nutrient which is used directly by the soil bacteria as well as by the plant, so that an increase in the amount of P in the soil often results in an increase of N. Because of P's low solubility, it is rarely leached from the soil. It is usually found in the greatest concentration in the soil's top layers, where it accumulates as a result of decomposition of organic matter.

In slightly acid organic soil, up to one percent of the total P is available at any time. The total amounts of P in soils range from 1,000 to 10,000 lbs per acre. For example, a typical Kansas prairie soil has 3,000 lbs per acre. In soils with a lower pH, more of the P is tied up in insoluble compounds of iron or aluminium. In highly alkaline soils, the P forms insoluble compounds with calcium.

Insoluble P reacts with the dilute acids that are released during decomposition of organic matter. These compounds are available to the plants. Both the chemical processes in which P is released and the organic processes of decomposition occur faster in warm soils.

If P is available, young plants absorb it rapidly, and may take in 50 percent of their lifetime intake by the time they are only 25 percent of their adult size. Young plants grown outdoors in cold weather may grow slowly until the soil warms up and more P is available. Older plants grown out of season in cold weather sometimes exhibit purple leaves. This condition may result from a P deficiency, because of the unavailability of P at low temperatures.

Most soil-test kits test available P, but the nutrient value of P is usually expressed as phosphoric acid (P2O5), which is converted using the formulas P * 2.3 = (P2O5),(P2O5) divided by 2.3 = P. Any soil that has available P of 25 lbs per acre (0.58 lbs per 1,000 sq.ft.) or more is well-supplied with P. Stated in terms of phosphoric acid, this is 25 * 2.3 = 57.5 lbs per acre (1.33 lbs per 1,000 sq.ft.).

Most inexpensive soil kits test available P. Soil that test less than 1 PPM or 10.7 lbs per acre (0.25 lbs per 1,000 sq.ft.) of available P should be tested to make sure there are adequate reserves, or can be fertilized to assure maximum yield. Soil-test kits give only a fair indication of the P available. A low reading may indicate the plants are absorbing P as fast as it breaks down from its unavailable form, especially during early growth! The main factors affecting the rate at which P becomes available are the total amount of reserve P in the soil and the pH.

Most professional soil analyses include a report of reserve P. Generally soils with reserve P of 3,000 lbs per acre (70 lbs per 1,000 sq.ft.) do not need additional P. Intensively cultivated and cropped fields may have had their reserve supply depleted, and will lock up available P that is supplied as fertilizer until a balance is reached.


K is found in adequate quantities in most soils which have a pH within the range needed for growing marijuana. K is held in soils in three forms: unavailable, fixed, and readily available. Most K is held in the unavailable form as part of the minerals feldspar and mica. But a small percentage of the total K in any soil is held in fixed, slightly soluble forms. Some of these can be absorbed and used directly by the plant. The exchangeable K is equal to a fraction of the fixed K. Each soil maintains a balance or ratio of unavailable to fixed and to exchangeable forms. Organic soils have a higher percentage of K in the fixed or available form than mineral soils. As K is used by the plants, some of the unavailable K goes into the more available forms. Plants can use K in both the soluble and the fixed forms.

Most clays and soils that are well-limed have adequate reserves of K. Acidic soils generally have low K reserves. Mucks, silts, and peats have low reserves of K, and have little capacity to hold it chemically when it is applied. Sands have K reserves, but little capacity to convert it to a fixed or available form. Most western soils have adequate reserves or K. The exchangeable K in soils becomes fixed if the soil dries out; so the available K of a recently dried soil is usually low.

K is tested in its elementary state, but when described as a nutrient, it is given as potash (K2O). The formulas for converting are K * 1.2 + (K2O),(K2O) divided by 1.2 + K. Soils with 180 lbs or more of available potash per acre (4 lbs per 1,000 sp.ft.) have an adequate supply. The total reserve K should test no lower than 900 lbs per acre (21 lbs per 1,000 sq. ft.).

The Secondary Nutrients

Magnesium (Mg), calcium (Ca), and sulfur (S) are usually found in adequate quantities in soils suitable for growing marijuana. However, some New England soils do have Mg deficiencies. Soils which have a neutral or near-neutral pH almost always have adequate Ca and sulfur levels.

Magnesium deficiencies are corrected by adding 50 to 100 lbs of Mg per acre (2.25 lbs per 1,000 sq.ft.). The most inexpensive way to add Mg is to use a dolomitic limestone for adjusting soil pH. Dolomitic limestone is about 12 percent Mg (see Table 21); so 800 lbs of it are needed to supply 100 lbs of Mg. Dolomitic limestone releases Mg to the soil gradually. For faster action, epsom salts (magnesium sulfate, MgSO4) can be used. Five hundred lbs of epsom salts are required to supply soil with 100 lbs of Mg. Mg deficiencies can also be corrected by using foliar sprays. Dissolve one ounce of epsom salts in a gallon of water and spray all foliage.

The relationship between soil pH and relative plant nutrient availability. The wider the bar, the more the availability. This chart is for soil types recommended in this book..

Nitrogen - pH of 6.3 to 8
Phosphorus - 6.5 to 7.5
Potassium - 6.5 to 9
Sulfur - 6 to 9
Calcium - 6.7 to 8.5
Magnesium - 6.5 to 8.5
Iron - <4 to 6
Manganese - 4.7 to 6.5
Boron - 5 to 7 or 9
Copper and Zinc - 5 to 7
Molybdenum - 7


Micronutrients are used by plants in minute quantities, and most soils contain enough of them to meet plant requirements. Home gardeners and guerrilla farmers seldom encounter any micronutrient deficiencies. But heavily cropped lands sometimes develop a deficiency of one or more micronutrients because of crop depletion. Micronutrients are made available to the plants only if there is a delicate balance in the soil chemistry, and it is easy to create toxic conditions by adding them to soil when they are not needed. For that reason, soils should be treated with micronutrients only when symptoms occur or when the deficiency is known by analysis or past experience. Only small quantities of additives are required for treatment. Manures, composts, other organic fertilizers, lime, rock powders, and ash contain large quantities of trace elements. Active organic additives quickly release micronutrients in a form that is available to the plants.


Boron deficiencies in marijuana occur in acid soils as a result of depletion by heaving cropping. The areas most affected by it are vegetable fields in the mid-Atlantic states, alfalfa and clover fields east of the Mississippi, and truck farms and orchards in the Northwest. Boron is found in phosphate fertilizers, gypsum, and lime, and is the main ingredient of boric acid and borax. When borax or boric acid are used, they are applied at the rate 10 to 20 lbs per acre. They are used as a foliar spray at the rate of 1 ounce per gallon of water.


Chlorine deficiency does not normally occur. Some chemical fertilizers contain chlorine, and toxic conditions occur infrequently. Toxic chlorine conditions are eliminated by leaching.


Copper deficiencies occur infrequently in truck farms in Florida, California, and the Great Lakes region. Wood shavings and tobacco contain large amounts of copper. A foliar spray composed of 1 ounce each of calcium hydroxide and copper sulfate (a fungicide) per gallon of water is used by commercial vegetable growers.


Iron deficiencies occur in orchards west of the Mississippi and in Florida, and in alkaline soils in which iron is largely insoluble. Lowering soil pH often solves the problem. Chelated iron, which is water-soluble, is available at most nurseries and quickly supplies iron even when pH is extreme. Humus and seaweed are excellent sources of iron.


Manganese deficiencies occur in the Atlantic states, the Great Lakes area, Utah, and Arizona. Manganese is found in manure, seaweed, and some forest leaf mould (especially hickory and white oak). Manganese deficiencies can be corrected by using a foliar spray of manganese sulfate at the rate of 0.5 to 1.0 oz. per gal. Soil is sometimes treated with manganese sulfate at the rate of 20 to 100 lbs per acre. In neutral or alkaline soils, most of the manganese sulfate becomes fixed and unavailable to the plants by the end of the growing season.


Molybdenum deficiencies occur primarily along the Atlantic and Gulf coasts and in the Great Lakes region. Plants need extremely small amounts of molybdenum, less than 1 PPM in leaf and stem tissue. Molybdenum deficiencies occur when the soil is too acidic. By raising the pH level, one can make molybdenum available.


Zinc deficiencies occur in soils throughout the U.S., primarily because of heavy cropping. It is most likely to occur in acid-leached sandy soils, and in neutral and alkaline soils where it is insoluble. In soils with high amounts of available P, zinc is also unavailable. Many deciduous tree leaves and twigs, composts, slag, and rock phosphate contain large amounts of zinc. Zinc sulfate is used as foliar spray at the rate of 3 oz. of zinc sulfate per gallon of water, or as a soil treatment at the rate of 100 lbs per acre. Some orchard growers drive galvanized nails into the trees to provide zinc.

2.6 fertilizers

Most soils can benefit from a realistic soil-conditioning program. Most organic programs build soil, and minimize leaching and runoff. Programs using chemical fertilizers emphasise immediate increase in yield and a minimum of labor. The approach that you use should be tailored to the soil's needs and to your situation and goals. For example, a home gardener interested in building soil quality can easily add manure or compost to his garden. But a guerrilla farmer may use concentrated chemical fertilizers, which are easy to transport to a remote area. A farmer cannot use the labor-intensive techniques which a small planter might use as a hobby. Many gardeners use both organic and inorganic fertilizers.

Organic fertilizers

Organic fertilizers are usually less concentrated than chemical mixes. Their bulk consists of fibrous materials which condition the soil by aiding drainage and increasing the organic content and water-holding capacity. As they are decomposed by microbial action, the nutrients they contain are released in soluble form. Since this is a gradual process, there is little chance of creating toxic conditions.

Manures and composts are basic, all-purpose conditioners. They contain adequate amounts of most of the nutrients that marijuana absorbs from the soil and can be used generously. Uncomposted manures are "active" and should be used only in the fall. Over the winter they compost in the ground. Composts and composted manures can be added in the spring. Table 22 lists some common organic fertilizers which are usually available. Some of them, such as bone meal and granite dust, break down slowly and are available only after a period of time. Others are low or lacking in one or more of the major nutrients. Organic fertilizers can be combined to provide a complete balance.

Chemical fertilizers

Most chemical fertilizers act quickly because all the nutrients are in soluble form. They are usually more concentrated than organic fertilizers, and can toxify the soil and kill the plants when they are overused. fertilizers come in various concentrations and ratios of nutrients. All packaged fertilizers list the percentages of N-P-K (actually n-(P2O5)-(K2O)). Also listed is the potential acidity or alkalinity, that is, the number of pounds of lime or sulfur required to counteract pH changes caused by the fertilizers. Chemical fertilizers are often incompatible with each other; so home gardeners who use them should buy them pre-mixed or as a complete component fertilizer set.

Solubility is a major problem with commercial fertilizers. In irrigated areas as well as areas with rainfall during the growing season, they are likely to be leached away; so they must often be applied several times during the growing season. A typical program might be to fertilize at planting and every six weeks thereafter until the beginning of flowering. When spreading fertilizers during the growing season, do not let them come into direct contact with the roots. An easy way to fertilize during the growing season is to make a small trough between rows with the corner of a hoe. fertilizer is placed in the depression. Some new chemical formulas release nutrients during the length of the growing season, and therefore need only one application.

Amounts to Use

The amounts of nutrient needed per acre and per 1,000 sq.ft. are shown in Table 23. Soils rich in one nutrient may be average or deficient in another. To calculate the required amount of a specific fertilizer, divide the amount of nutrient required as listed in the chart by the percentage of nutrient in the fertilizer. For instance, to add 5 lbs of N to an area by using bloodmeal, divide 5.00 by 0.12. The total comes to a little more than 33 lbs. Dried cow manure contains about 1.5 percent N. About 333 pounds of it are needed to supply 5 lbs of N. Urea, a chemical fertilizer, contains 46 percent N. Only 11 pounds are required to supply 5 lbs of N.

Planning a Garden fertilizer Program

Now let's plan some garden fertilization programs, to help some cultivators in three areas which have different soils and climates: New England, Kansas, and Florida. We'll see how growers with different goals adjust their garden soil.

New England

Most New England soils, and many soils in humid temperate areas, have a thick layer of humus which supplies N. New England soils also contain moderate amounts of P, but they are low in K.

Our first gardener has a typical New England soil in his backyard. From tests and observation he thinks his soil contains moderate amounts of N and P, but is low in K. A test indicated a pH of 5.8. He plans to start preparing his ten-foot-square plot (100 sq.ft.) in the fall, before frost. By planting time, he expects his backyard garden to have a pH of 6.7 and a balanced, fertile soil.

From Figure 59 he finds that the soil requires about 8.1 lbs of lime. He has decided to adjust the pH by using dolomitic limestone (with a calcium carbonate equivalent of 0.45) because farmers in the area sometimes complain of Mg deficiencies. Dividing 8.1 by 0.45, he finds that the soil requires 18 lbs of limestone. (Lime requirements divided by calcium carbonate equivalent equals the amount of limestone needed.)

He guesstimates that the N content of his soil rates between fair and medium, and figures the soil can use almost 0.2 lbs of N. He has decided to spread fresh manure from a nearby stable mixed with lime. In the spring he will turn this into the soil; at the same time, he will add manure composted with hay and table scraps. The fresh horse manure contains about 0.44 percent N. To find out how much manure he needs, he divides 0.2 (the amount of N required) by 0.0044. The total comes to about 45.5 lbs. (Nutrient required divided by percentage in fertilizer equals amount of fertilizer needed.) The manure also contains 0.17 percent phosphoric acid (P2O5) and 0.35 percent potash (K2O), referred to hereafter in this chapter as P and K, respectively. Multiplying 0.17 percent (0.0017) and 0.35 percent (0.0035) by 66 lbs, he finds that he has added 0.11 lbs of P and 0.23 lbs of K. (Lbs of fertilizer times percentage of nutrient in fertilizer equals amount of nutrient in fertilizer.)
Chemical fertilizers usually supply P in the form of superphosphate or triple superphosphate. These chemicals are manufactured by mixing rock phosphate with acids. Potassium is supplied by means or muriate of potassium (K and chlorine) or sulfate or potash, which are mined in the Southwest and purified. All these chemicals are soluble and are available to the plant. But a portion of them gradually reacts with the soil and becomes fixed or unavailable. As this portion becomes unavailable, it increases the total reserve in the soil, which reaches a new balance of available to unavailable nutrients than before fertilization.
Bone meals and rock phosphate, the most commonly used organic sources of P, and granite dust, a source of K, are not readily available, but increase the total reserve of nutrients and gradually increase the total amount of available nutrients. However, there is some time lag before these nutrients are available to the plant. They are usually applied in large amounts, at about three times the weight calculated for fertilizers of that concentration. But one treatment lasts four years or more, because the fertilizers remain fixed in the ground until they are used.

From Table 23 he finds that the soil requires about five ounces of P. How many ounces of P is 0.11 lbs? He multiplies 0.11 by 16, the number of ounces in a pound, and finds that the total is about 1.75 ounces. The soil requires another 3.25 ounces. Bone meal is about 20 percent P. To supply three ounces of P, about a pound of bone meal is required. But bone meal breaks down slowly, and is therefore applied at three times the rate used for other fertilizers; so our cultivator uses 3 lbs.

Since the K content of this New England soil is poor, about 0.3 lbs of K is required. The manure has already supplied 0.2 lbs; so the soil requires another 0.1 lb. Our cultivator decides to use wood ashes from his fireplace. Wood ashes are about 7.0 percent K. He divides 0.1 by 7 percent (0.07) and finds that the soil can use at least 1.4 lbs of ashes. He adds this in the spring just before planting, because the ashes are highly soluble. Over the winter, such highly soluble nutrients would leach away or become unavailable.

Our grower knows that some of the N in the fresh manure that was added in the fall will leach away during the winter. But the manure compost that he adds in the spring will more than make up for any losses.

A New England farmer not for from the cultivator has been rotating his field from corn and marijuana to alfalfa and pasture for the past ten years. Each fall he adds 7 tons of manure per acre. Except for occasional additions of lime, no other fertilization is necessary.

A rural New England grower has decided to plant in a remote mixed-forest area. The first 10 inches of soil is a rich compost of humus. It is full of life: insects, worms, and other creatures. The grower has decided to increase the fertility of the soil by using chemical mixes and dolomitic lime. He is cultivating in three clearings with a total area of about 1,000 sq.ft. He guesstimates that the soil is medium in N and P, but poor in K. It is also acid. He applied enough lime to correct the soil's natural acidity and the pH of the fertilizer.

Using Table 23, he decides that he should purchase a mix with a ratio of 50 parts of N, 10 parts of P (reading from the medium line), and 120 parts of K (from the poor line), that is, a ratio of 5-1-12. A local nursery sells commercial fertilizer with nutrient percentages of 10-5-25, close enough to the desired ratio. By taking the total amount of N required for a medium soil as listed in Table 23 (19 ounces), and dividing it by the N in the fertilizer (10 percent or 0.10), the rural grower finds the total amount of fertilizer required (190 ounces, or a little less than 12 lbs). The other nutrients are automatically added in the same ratio.

Kansas: A cultivator in Kansas decides to plant along a hidden stream bank. The banks are covered with lush vegetation as a result of runoff that contains soluble fertilizers used on nearby farms. The cultivator feels that additional fertilizers are not necessary, since the vegetation is so lush.

Another grower in Kansas found that her soil was very low in N and P, but high in K, typical of dry midwestern and western soils that support scrub vegetation. It had a nearly ideal pH. She started to prepare her 200 sq.ft. garden in the spring after the rain season ended. Using Table 23, she found that it required 3.5 lbs of N, 6 ounces of P, and no K. Activated sludge (5-3-0) was available at the local garden center. To find out how much sludge her garden required, divide 3.5 by 5 percent (or 0.05). The total comes to 70 lbs.

Florida: A grower planting 500 sq.ft. on a deserted ranch in central Florida started with a very sandy soil whose pH was 4.9 because of sulfurous water in the ground. From Figure 59, she found that the soil required about 35 lbs of lime. To adjust the pH, she used 11.0 lbs of a limestone with a calcium carbonate equivalent of 2.5.

The soil had virtually no organic matter, and she was not sure she could use the same location next year; so she decided to apply soluble mixes throughout the growing season. From Table 23, she found that "poor" required 28 ounces of N, 4 ounces of P, and 24 ounces of K. A chemical fertilizer with nutrient percentages of 15-5-10 was on sale at a local discount store. To find out how much fertilizer is needed to supply 28 ounces of N, divide 28 by 15 percent (or 0.15); the result is about 186 ounces of N, or about 11.5 pounds. Since the other nutrients are supplied at the same proportions or at higher proportions than are required, no supplements are needed at planting time. But additional feedings will be required periodically during the growing season.

2.7 Techniques for Preparing Soils

Each garden situation is unique, and many factors help determine which garden techniques you should use. These include the soil's condition, the size and location of the garden, commitment, and personal preferences. Each technique affects the microecology in its own way. Home gardeners may use techniques that are impractical for a farmer or guerrilla planter. But all growers have the same goal when they prepare soil for planting: to create a soil environment conducive to growing a healthy, vigorous plant.
BOX G Fertilizing Cannabis Depends on the Crop
Historically, Cannabis is known to require high fertility. In a fertile soil, Cannabis can outgrow practically any annual plant. Cannabis also is a known depleter of soils. This is true particularly with marijuana, since seeds, flowers, and leaves comprise the harvest. Hence it's necessary to fertilize the plants each year. Hemp, on the other hand, comes from the Cannabis stem, and the fibre consists primarily of cellulose (C6H10O5)n. When hemp is grown, all plant parts except the fibre are returned to the soil; so the nutrients are also returned. Moderate fertilization, if any, is all that's required for hemp farmers.

If you are already growing a vegetable garden, the chances are that your soil is in pretty good shape for growing marijuana. However, vegetable gardens may be a little acidic, particularly east of the 100th meridian. The soil should be prepared in much the same way that it is prepared for corn cultivation, with the addition of lime to raise the pH to near neutral.


Gardens which may not have been planted recently (in the last three or four years) require more work. It is best to begin preparing the soil in the fall, before the first frost. This can be done using a spade or shovel. The ground is lifted from a depth os six or eight inches and turned over so that the top level, with its grass and weeds, becomes the bottom layer. Large clumps are broken up with a blade or hoe. Larger areas can be turned with a power hoer or rototiller. Conditioners, such as fresh leaves, composts, mulching materials, pH adjusters, and slow-release fertilizers are added and worked into the soil, so that they begin to decompose during the winter. It is especially important to add these materials if the soil is packed, mucky, or clay-like. Soluble fertilizers should not be added in the fall, since they leach to the subsoil with heavy rains.

In the spring, as soon as the ground is workable, turn it once again. If the soil still feels packed, add more conditioners. If you are using manure or other organic materials, make sure that they are well decomposed and small clean and earthy. Fresh materials tie up the N in the soil while they cure, making this nutrient unavailable to the plants. Commercial fertilizers and readily soluble organics, such as blood meal and wood ash, are added at this time.

The ground can also be seeded with clover or other legumes. Legumes (alfalfa, clover, vetch, etc.) are plants which form little nodules along their roots. The nodules contain bacteria which live in a symbiotic relationship with the plant. As part of their life processes, these bacteria absorb gaseous nitrogen from the air and convert it into a chemical form the plant can use. During its life cycle, clover uses up most of the N, although some leaks into the surrounding soil. But when the plant, or any of its leaves, die, the contents become part of the soil. The process of growing a cover crop and turning it into the soil is sometimes called green manuring.

After the last threat of frost, at about the same time that corn is planted, the soil should be worked into rows or mounds, or be hoed. At this time, the seeds should be planted. If any concentrated fertilizer is added to the soil, it should be worked into the soil and should not come into direct contact with the seeds.

The actual amount of tilling that a given soil requires depends on soil condition. Sandy soils and light loams may need no turning, since they are already loose enough to permit the roots to penetrate. Turning may break up the soil structure, damaging its ecology. These soils are easily fertilized, by using soluble mixes or by the layering technique described below. Soils which are moderately sandy can be adjusted by "breaking" and levered or pushed, but the soil is not raised. This is done about every six inches, and can be accomplished quickly. Farmers can loosen sandy soil by disking at five or six inches.

Some gardeners mulch the soil with a layer of leaves or other materials to protect it from winter winds and weather. This helps keep the soil warm so that it can be worked earlier in the spring. In states that border west of the 100th meridian, this helps prevent soil loss due to erosion from dry winds. Soil often drains well in these areas, and the ecology of the soil is better served when it is left unturned. At season's end, marijuana's stem base and root system are left in the ground to help hold topsoil. The next year's crop is planted a cover crop, such as clover, or alfalfa, which holds the soil and also enriches the nitrogen supply.


Layering is another method of cultivation. The theory behind this program is that in nature the soil is rarely turned, but builds up, as layer after layer of compostable material falls to the ground. This material, which contains many nutrients, gradually breaks down, creating a rich humus layer over a period of years.

The layering method speeds up the natural process. Since gardens are more intensely cultivated than wild fields, new material is required to replenish the soil nutrients. Gardeners like Ruth Stout "sheet compost," that is, they lay down layers of uncomposted material and let it decompose at the same time that it serves as a mulch. But most gardeners prefer to use material which is already composted. The compost shrinks and builds the topsoil layer about an inch for every six inches of compost. After several years, the soil level will be raised considerably, and the top layers will be an extremely rich, porous medium which never needs turning. In order to prevent a spillover of the soil, gardeners usually construct simple beds (using boards) to contain the garden areas.

Layering is most successfully used on porous soils, especially sands, which contain little organic matter. It can also be used with clay soils. However, experienced growers say that clays should be turned several times before the technique is used, or the first couple of harvests will be small.

Planting a cover crop such as clover will give the soil structure. As more compost is added, the clover is covered and the new seed planted. The clover, with its N-fixing properties, remains a permanent cover crop. When marijuana seeds are to be planted, a planting row is easily tilled with a hoe. The clover protects the soil from sun-baking and its resulting water loss, and makes it harder for weed seeds to get started.

Tilling and layering are basic methods which are used with many variations. In some ways, there almost seem to be as many gardening techniques as there are gardeners. For instance, one gardener bought three cubic yards of topsoil and a cubic yard of composted steer manure. He mixed the material and filled raised beds with it to a depth of 18 inches, and had an instant high-power garden. Another grower made compost piles in his raised troughs during the winter. By planting time, the compost was complete and filled with earthworms. The beds became warmer earlier, and he could plant sooner.

A midwestern gardener used marijuana as a companion crop in much the same way Indians used corn. In between the marijuana, she planted beans and squash. She didn't get many stringbeans and only a few squash. But she believes that the beans gave the plants extra N, especially during the first six weeks, and the broad squash leaves protected the soil from the hot August sun.

A gardener in Georgia had such a sticky clay soil that a shovel once got stuck in it. He dug holes two feet deep and two feet wide with a power auger and filled them with a fertile mix of two parts sand, one part clay, three parts topsoil, and one part chicken manure. He claimed that his plants grew six feet in 10 weeks. Filling holes with a rich soil mixture is popular with guerrilla farmers, who often must plant in poor native soils.


Mulching is a labor-saving technique that many gardeners and farmers use for a multitude of reasons. A mulch placed on the ground before fall frosts helps the soil retain heat and protects it from winds and freezing temperatures. In the spring the mulched soil becomes warmer earlier in the season, and can be planted several weeks sooner than usual. A mulch cover keeps the seedlings' roots warm and eliminates a lot of weeding, since most weed seedlings cannot pierce the cover.

During the summer, mulches keep the ground cooler and more moist by absorbing and reflecting light and reducing surface evaporation. These are important points for farmers in dry areas. The water savings can be 50 percent or more.

Any plant or animal material will do for mulch. Gardeners use hay or straw, leaves, composts, manures, sawdust, bark, or plant clippings in two- to six-inch layers. A barber in Palo Alto uses hair. Baled hay is inexpensive and easy to use as a mulch. Round hay bales unroll in a long sheet that is easy to spread over the ground, and square bales can be pulled apart into tile-like squares.

Mulches create an ideal environment for earthworms and microorganisms which condition and enrich the soil. These organisms require a relatively cool, moist, dark environment. The mulch develops a dry outer crust which reflects light, keeping the underlayers cool and moist. Materials such as leaves, bark, and sawdust decay slowly because they do not contain enough nitrogen to maintain dense populations of decomposing microorganisms. Manures and composts contain more nitrogen and decay more quickly.

With few exceptions, mulches can be applied practically any time of the year, but the best time is probably in the fall, after the crop is harvested and before the ground has frozen. Leaves, plant clippings, and straw are applied in a thick layer from six to ten inches deep. Hay is layered two to six inches deep. Denser substances, such as manures and composts, should be mixed with straw and leaves to aid decomposition. This mixture is spread in an even layer, about two to four inches deep, over the entire surface of the garden. If winds pose a problem by blowing the mulch away, you can cover it with newspapers or sheets of plastic held down with rocks. If your area is dry, give the mulch a good soaking once before frosts.

By the spring, much of the material will seem to have disappeared. But underneath the top layer, you will find a soft-textured, earthy-smelling humus, teeming with worms, insects and other small animals. This is a sign of a healthy ecosystem and a fertile soil.

Some people apply mulch in the spring, placing it between rows as they sow the seeds. The mulch keeps weeds from competing with the seedlings, absorbs the sun's warmth, and releases nutrients to the soil.

In cold areas, such as Montana, New England, and Alaska, growers place black plastic sheets over the soil. These absorb the sun's heat, allowing the soil to be planted sooner. The seedlings develop quickly in the warmer soil. The plastic is removed once the seedlings are well-established.

Newspapers and white plastic can be used to decrease water loss during the summer. They also reflect light back to the plants.

One innovative grower from western Colorado placed a sheet of white plastic over her garden and cut out holes wherever she plant the seeds. Though it is quite dry where she lives, she didn't need to water the plants until late July. And she had no problems with any weeds.


Containers are another option open to grower. Plants can be grown full-size in containers which are at least five gallons (larger would be better). Fill them with high-grade topsoil, or a plating mixture as described in section 6. Planters are a convenient compromise where the soil is particularly poor or for the home gardener who does not wish to get into large-scale gardening. But remember, eight good-sized plants can yield over four pounds of grass.

Plants in pots need to be watered frequently, but require much less total water than a garden. The gardener can also move the plants. Some gardeners use this technique to maximize the amount of sun the plants get during the day, or as the sun's position changes with the season. And growers can easily induce early flowering by moving the plants to a darkened area.

Almost any large container that can withstand the weight of moist soil and which has holes for drainage is suitable. Containers which held toxic chemicals, herbicides, insecticides, or other possibly harmful substances should be avoided.

We have seen all kinds of ingeniously made containers. Some growers use old bathtubs, and others use wooden packing crates or bushel baskets. A simple wood container 18 inches wide, eight feet long, and 18 inches deep was made by a New Jersey grower, who grew six plants in it. Trash cans, plastic containers, barrels, and even rubber tyres have been used. One grower grew plants in one-cubic-foot bags of soil by cutting a five-inch-diameter hole in the top and poling holes for drainage. To assure drainage, growers sometimes fill the bottom of each container with a six-inch layer of stones or gravel; is you are planning to move such container, lightweight perlite would be more suitable.

2.8 guerrilla Farming

guerrilla growers often use the same techniques as home gardeners. But the soil that they start with is sometimes marginal, and the gardens are in remote, hard-to-get-to areas; so they modify the techniques to fit their needs. When it is impractical to carry bulky organic fertilizers to the growing site, guerrilla farmers use highly concentrated commercial mixes. Compost and soil adjusters are gathered from the surrounding area, and the simplest, most light-weight tools are used. Some growers use horses or mules to carry equipment and material, and then use the animal to plough. The animals are quiet and, naturally, require no external power source. Experienced growers say that the animals can work as fast as or faster than a rototiller.

It is hard to generalize about details of guerrilla farming, since much depends on the specific circumstances, which can vary greatly. For instance, a grower who plants along the fertile bank of a midwestern stream may not need to do more than pull out weeds and till the actual planting area. But a grower planting on a mountain slope may have to "build a soil," since soil and nutrients are washed from the slopes and down to the valleys by rainfall. For this reason, we will cover several situations separately: forest; washed-out steep areas; swamps and marshes; stream banks; grasslands and fields; and arid soils.

Forest Clearings

Clearings in forests have always been popular places to plant because they offer security from detection. They vary greatly in drainage qualities, fertility, and pH. The drainage qualities of forest soils depend on the depth of the humus layer and the structure of the underlying subsoil. But most of the forest remaining in the U.S. is sloped, and water that is not absorbed by the soil runs off.

Soils are created in forests from the leaves, branches, animal droppings, etc., which accumulate on the forest floor. The first trees to grow are long-leaf pines, such as jack pines, which can grow in relatively infertile soils. Their roots penetrate deep into the subsoil to obtain some nutrients. Short-leaf pines, conifers, and firs appear as the humus accumulates, since they require a more fertile soil than long-leaf pines. Pine-forest soils vary in fertility from poor to fair, and are usually quite acidic. In the Northeast their pH may be as low as 3.5, but generally the pH ranges from 5.0 to 6.0. In order to support a high-energy, lime loving crop like marijuana, they require fertilization and liming. Long-leaf pines sometimes grow in compacted clay soils, which also requires tilling.

As the soil evolves, deciduous trees (tree that drop their leaves each winter), such as oak and maple, may begin to grow. Deciduous forests, sometimes called broad-leaf or hardwood forests, have the best soils. These forest floors are covered with bushes, grasses, mosses, and other small plants. They have an adequate rainfall and a humus-rich soil, which is porous, holds water well, and can support a healthy marijuana crop, although additions of nitrogen fertilizers would probably spur growth. Hardwood forest soils have a pH range from 6.0 to 7.5. The soil in timbered forest land has a much smaller humus content, especially if it has been clearcut.

Mountain Soils and Washed-Out Steep Areas

Mountain slops characteristically have little soil matter; their surface is composed largely of rocks, gravel, and sand. For longterm use they could be terraced so the newly formed soil in not washed away, but most growers are interested in more immediate results. These "soils" do not provide much of an anchor for marijuana's taproot and do not permit a network of lateral roots to form. Many of these soils also suffer from a low water table, since they drain rapidly. But there may be some sand and a bit of organic matter built up along gullies or in depressions or other natural traps. Such soil has usually had most of its nutrients leached out, but may contain some phosphates and potassium and considerable amounts of trace elements. The easiest way to adjust these soils is to use a well-balanced, slow-release, concentrated fertilizer. Bloodmeal, with its high N, works well with these soils.

One grower in the badlands of North Dakota used a timed-release 32-9-26 fertilizer in his "rock garden." He spread it just below the surface at the beginning of the growing season. Every time that it rained, his plants received nutrient-rich water. Toward the middle of the season, he noticed the lower leaves begin to pale, so he fertilized them periodically with urea. Heavy rains leach soluble fertilizers away, and in rainy areas they need to be applied three to four times during growth.

Containers can also be used in this environment. Growers use plastic bags or folded milk cartons instead of backpacking with a column of containers. When they get to the site, they fill the bags with a mixture of sand, as much as they can find, and gravel. The greater the ratio of sand to gravel, the longer the container will hold water.

One grower doublelayers heavy-duty polyethylene bags, and lines them with heavy-duty paper cement sacks or burlap bags. He fills the bag with gravel, then pours in sand and shakes it. He says that the mix is just about right when it looks like a can filled with gravel with sand in the spaces. He carries on a watering and feeding program much as he would for any hydroponic system.

Swamps, Marshes, or Bogs

These soils are very high in fibrous organic material, but are low in calcium and in available N, P, K, and Mg, which are leached from the soil or are insoluble because of the low soil pH. Since these soils are constantly wet, Cannabis roots cannot come in contact with air; as a result, the plant's growth is stunted, and the lower stem becomes susceptible to stem rot. These soils need to be adjusted to support a healthy crop of marijuana; they must be drained, fertilized, and limed. On a small scale, the easiest way to modify them is by constructing raised mounds, hills, or rows, at least one foot wide at the top and two feet high. The raised areas drain well, leaving relatively dry soil. Wood chips, chopped brush, sawdust, or perlite may be added to keep the mound light and the soil loose and aerated.

Wet soils are usually highly acid and should be limed. Once the lime interacts with the soil, nutrients which were locked up become available to the plants. Since these soils are rich in organic matter and have a high rate of microbial action after they are loosened and limes, they may need little fertilization.

Grasslands and Fields

These soils are usually fairly fertile and can support a worthwhile crop with little effort. They are usually well-drained, although they may be a little too dry or too wet. (If they have unusually large numbers of earthworms, they are probably a little too wet.) Their pH is usually between 5.5 and 6.5, although it may range up to 7.0. These soils are usually loams, which need only tilling in a two-foot radius, three or four inches deep, around each plant. All weeds and grass should be pulled from the area. Some growers mulch the cultivated area with newspapers, leaves, or dead grass. A grower in the Midwest adds crushed eggshells and a commercial timed-release fertilizer when he plants. He feels that this "extra boost" makes the difference between an adequate crop and a bountiful crop. Other growers periodically fertilize with soluble mixes. Some of these soils have to be irrigates during the long summer droughts. If they aren't, the plants won't die, but they will not grow to full size.

Stream Banks and Canal Ditches

These are some of the most convenient areas for growers to plant, since they provide an ample supply of water, which may contain fertilizer runoff. Stream banks are an area that marijuana naturally colonizes, and the planter usually needs only to cultivate the area to be sown, and cut surrounding bush so that the young plants can compete with established plants. It the surrounding vegetation looks pale and stunted rather than lush green and vigorous, the soil should be fertilized. These soils are sometimes low in calcium, which dissolves readily in water. Lime should be added to correct for acidity.

Sometimes the ground is a little too wet early in the growing season, although it dries out later on. Planting on hills or mounds is often used to solve this problem.

Arid Areas

Soils which have a low water table and dry out by June or July need to be irrigated to grow marijuana successfully. When irrigation is not feasible, growers plant along drainage ditches, streams, and canals, or look for green spots which indicate springs or underground reservoirs. Other growers use containers to minimize water loss. One grower in Arizona dug holes two feet wide and three feet deep, and lined the sides with thin polyethylene. He said that when he watered during the summer drought, he did not lose much water to the surrounding soil.

Arid soils usually have little organic matter, and drain quickly with extensive runoff. Some of them have a subsurface layer of clay, and therefore hold water on the surface until it evaporates. In any case their texture can be improved greatly by working in organic matter. The soil should be loosened at least two feet down. This loosening allows the taproot to develop deeply so that it can reach underground water during the drought.

Arid soils more often drain well, are alkaline, and contain P, K, and trace elements, but are low in N. Fish meal, cottonseed meal, blood meal, or manure may be the only additive the soil needs.


After the soil is adjusted, you are ready to prepare it for planting the seed. Sowing is an important process, since the post-germination or seedling stage is the most critical for Cannabis. You can increase the seedlings' chance of survival by sowing the seeds properly.

3.2 When to Plant

Most hemp-growing manuals advise that the seeds should be planted about two weeks after the last threat of frost, which is the same time that corn is planted. As a rule of thumb, you need not plant until this time in areas that have a growing season of five months or more. These areas include most of the United States, except for Zone One (see Figure 62) and mountainous areas of the country.

Growers in northern areas report that plant have survived light evening frosts with little or no damage. We think of marijuana as a tropical plant, experiencing no chills in its native climes. But the mountainous areas of marijuana cultivation in Mexico and Colombia often have frosts during the growing season. One grower, describing spring (April) conditions in Nebraska, reported "plants (from tropical seed) three and four inches tall were covered with snow in the evening. By midafternoon all the snow had melted, and those little sprouts were healthy as could be."

Early-season sprouts do face more risks than later-germinating plants do. A lingering freeze or chill can weaken or kill them. Sometimes seeds or seedlings get washed away be heavy rains or flooding, or become infected from wet soil. They are also prey to hungry herbivores, who savour the tender young shoots, especially in the early spring, before the native plants have sprouted. These predators include rabbits, groundhogs, rats, mice, and possibly squirrels and cats, as well as large animals, such as deer, cattle, and sheep. Birds frequently eat the seeds and young shoots, especially if the ground looks planted. Snails and insects, such as cutworms and leafhoppers, also eat seedlings. Don't let this impressive list of dangers dim your enthusiasm. Although these problems do occur, they can be controlled or prevented with a little but of planning (see section 13).

As you can see in the Spring Thaw map , the last date of expected frost varies from early February in parts of Florida, Louisiana, Texas, California, and Nevada to mid-June in the coldest regions of New England and the Midwest. Planting time varies locally, as well as regionally. Fields which receive direct sun warm faster than partially shaded ones. Fields covered with a layer of compost or fresh manure, or with black plastic sheets, retain more heat and are ready to plant sooner than other fields. Mountainous areas often vary considerably in planting time. Higher ground usually stays cold longer than low-lying areas. Since soil is dark, it heats quickly when exposed to sunlight. Soil is usually warmer in the late afternoon.

The time that the soil warms also depends on the weather. During severe winters, a deeper layer of soil becomes frozen than during mild winters; so it will take longer to thaw. Soil below this layer is insulated by the ice and remains unfrozen. Spring weather, rainfall, flooding, and cloud cover also affect the soil's temperature.

Actually, the only way to know whether or not a field is ready to plant is to feel it and look at it. Examine the soil in early morning. It should be easy to work, rather than hardened from ice. There should be no large frozen clods of soil or other organic matter. There should also be no fine crystalline ice particles which glimmer in sunlight.

For fall harvest, sow outdoors after March 21, the first day of spring and the turn of the Equinox, when there are equal lengths of sun-up and sun-down. There are an additional 20 to 30 minutes of light before dawn and after sunset, for a total of 13 hours of daylight. When plants are started earlier, they may flower prematurely because of the short days. The plants may also be subject to sex reversal, and more males may develop.

There is little advantage to starting Cannabis before April. Each plant has a certain genetically defined potential for growth and size. As long as the plants have enough time to grow and develop, usually five or six months, this potential is realized (some Colombian and Asian varieties may need longer to develop). Plants started before spring grow no larger in size than plants started during April. The younger plants are virtually indistinguishable from the older ones by harvest, and plants which are started earlier face more risks of detection and destruction.

However, if you are faced with a short growing season, you can get a head start by germinating the seeds a week to six weeks before the local planting time, and transplanting the seedlings outdoors at about the same time seeds would be planted in your area. You can also hasten planting time by covering the area to be sown or planted with a clear (or black) plastic sheet, which will warm the ground by the greenhouse effect.

3.3 Preparing to Sow

Growers sue three basic techniques to sow marijuana: rows, hills, and broadcast. Each method is suitable within a certain range of conditions and has its own advantages and disadvantages.


Rows are convenient to use, especially for large areas. They are constructed easily using a how, plough, or tiller.

Rows facilitate the care of gardens and fields by setting up an organized space in which the plants and surrounding area can be reached easily by the gardener. Weeding, watering, thinning, pruning, and harvesting can be accomplished very quickly. Larger fields are planted in roes to accommodate ploughs, planters, and cultivators. They are essential when fields are flood-irrigated. Furthermore, they provide a way to use space in the most efficient possible manner. But rows make detection easier, since they have an orderliness that plants do not exhibit in nature.

On sloping and hilly ground rows are a major factor in soil conservation: such soil is easily carried away in windstorms and in the runoff after rain. For this reason, rows on hilly and sloping ground are contoured: curved to run perpendicular to the slope.

Space rows two to six feet apart; plant seeds every four to eight inches ((In any description of planting which we give, we refer to 100 percent viable seeds. In this case, for example, if seeds are tested (see section 3) and have a viability of 50 percent, sow the seeds two to four inches apart. If they have a viability of 33 percent, sow them one to two inches apart.)) (See Box H.)

To construct a row, break up any large clods on the surface of the soil. In a garden-size area this is easily done by striking them with the tongs of a rake. In larger areas a tiller or externally powered cultivator can be used. Then level the soil.

If you need to irrigate or have problems with excessive moisture, use a hoe to raise the soil in alternate rows of hills and trenches. Pat the crests of the hills with the hoe or a shovel so that they are an inch or wider at the top, and four to eight inches high than the trenches.

BOX H Plant Size and Spacing

Plants vary tremendously in size and branching habits because of many factors, including variety, soil fertility, length of growing season, amount of light received by the plant, water, spacing, and pruning. As a result, one can have no firm rule about how far apart plants should be spaced.

An individual full-grown plant may have a diameter at its base as wide as ten feet or as small as 18 inches. Most conical-shaped varieties (Colombian and Jamaican) grow between seven and 12 feet tall, and have a width between four and six feet. Mexican plants are somewhat taller and thinner, with a base diameter of three to five feet. Some exotic Indian, Central Asian, and Central African plants may have a diameter only one or two feet across. The descriptions are generalizations; there are many varieties within each country, and much variation within each variety.

Pruned plants have a much wider base than unpruned ones. Plants pruned at the fourth internode and again a month later sometimes grow twice as wide as an unpruned plant.

In order to catch as much sun as possible, rows should be orientated along a north-south axis, perpendicular to the course of the sun. The advantage of lush rows is more pronounced in southern than northern latitudes, but the solar-energy differential in north-south versus east-west rows is significant at all latitudes in the United States, and becomes more important on steep slops. Another factor is the orientation of the garden as a whole. Plants sown in a square plot whose sides point northeast and southeast get about 10 percent more light than ones in a plot whose sides point due north and due east.


Hills and mounds are especially convenient for small plots. Low hills are often camouflaged to look like natural or wild stands, and are very useful in areas in which the land is too wet in the spring, because the hills drain above the ground level. They are easily adapted to meet unusual requirements. For example, a grower in New Mexico planted a doughnut-shaped hill eight feet in diameter and two feet thick, leaving a center hole four feet in diameter. He placed a portable plastic tub in the hole after punching pinholes around the edges. To water he just filled the tub. In the swampy Everglades, two industrious farmers constructed a giant hill-row three feet thick and three feet high. The hill had such a good drainage that it kept the plant roots well-drained even during the rainy season.

Hills are usually constructed between two and five feet in diameter. Small hills are usually planted with 15 to 20 seeds, and large ones may be sown with as many as a hundred. The hills are spaced three to 10 feet apart, so that each groups of plants gets a maximum amount of light. Hills can grow more than you would at first suspect. For instance, if you were to grow a hill three by three feet, you could harvest six to nine large plants. Their foliage would extend two and a half feet beyond the hill, for a total of about thirty square feet of foliage space.

Broadcast Seeding

Broadcast seeding is the fastest and easiest way to sow, but is not an efficient way to use seed. Seeds are simply tossed or shaken onto the prepared ground, at the rate of about forty per square foot, and are then usually pressed into the soil with a light roller or by foot. This method is most effective in moist soils. Many of the seeds never germinate or die immediately after germination. The faster growing ones naturally stunt the others by shading them. This method is often used by guerrilla farmers who want the stands to look natural and who wish to plant large areas quickly. An experienced grower can sow several acres a day by hand using this method.

Seed Count

There are approximately 2,300 medium-sized seeds in an ounce, or about 85 per gram. An acre is about 43,000 sq. ft., or a square 208 feet on side. To plant an acre in rows two feet apart with a seed every four inches requires about 90,000 seeds or 39 ounces (1,100 grams, or two pounds, seven ounces). At this rate, a ten-by-ten plot requires about 2.5 grams of seed.

A typical hill field has four-foot-wide hills spaced about seven feet apart. A typical hill and surrounding area accounts for approximately 100 square feet. There are approximately 430 hills in an acre. If each of these is planted with 100 seeds, the field requires about 43,000 seeds, which weigh about 18 ounces.

Broadcasting requires a lot more seed. At the rate of 40 seeds per square foot, a grower uses about 2.3 ounces in a ten-by-ten plot. An acre requires about 47 pounds, or 21 kilograms of seed.

How to Plant

Finally, after the soil is adjusted, and the rows or hills are built, it is time to actually plant the seeds and watch your garden begin to grow. If you are growing with clover as a cover or companion plant, dig it up to a depth of four inches and chop up the soil. Water the soil to the point that it feels almost wet. Drill a hole with a seed drill, stick, or pencil, then drop one seed into the hole, cover it gently, and pat the soil down again. Marijuana seeds are large enough to handle individually; so each one can be planted separately.

How deep one digs the holes depends on the kind of soil in which one is planting. Light woodsy or organic soils are planted 1/2 to 3/4 inch deep, so that the stem is held firmly in an upright position. Sands and light loams are planted 1/2 inch deep. Heavy loams and clay are planted 1/4 to 1/2 inch deep, so that the sprout's energy is not expended before it breaks through the soil.

If you are broadcast seeding, you can increase the germination rate tremendously by screening a layer of soil over the seeds to help keep them moist. Seeds that dry out weaken or die.

In a garden that has been mulched, lift away the mulch cover at each place you plant, and sow the seed in the underlying soil.

In soft-textured soils, instead of digging or poking holes, press each seed to the desired depth, and cover or pat the soil smooth.

3.4 Germination

The seeds need constant moisture in order to germinate. Therefore, the ground should be well-watered. Keep the soil moist by watering it with a light spray whenever it begin to feel dry. This may mean watering the immediate area once a day. You can keep the soil moist and hasten germination by covering the planted area with transparent glass or plastic. Most of the seeds should sprout in a period ranging from three days to two weeks. This variation depends on variety, age and condition of seed, and soil temperature; the warmer the soil, the faster the rate of germination.

Once they have germinated, the seedlings should be kept moist until the roots grow deep enough to absorb an adequate supply of water from the subsoil. If the ground is still moist from spring rains, as it is in many of the eastern regions, you may not have to water at all. On the other hand, there are sections of the West which are completely dependent on irrigation.

When the seedlings are only an inch or two tall, you can protect them from heavy rains or frosts by using drinking glasses, jars, or paper or plastic cups. You can protect larger plants with containers from which the bottoms have been removed. Transparent containers warm the soil by the greenhouse effect, capturing light and turning it into heat. In warm weather, use white or translucent containers, which prevent burn by reflecting some light and diffusing the rest. Containers also keep the soil moist, serve as plant markers, and protect the plants from some enemies. A grower in Berkeley, California, used cracked fish tanks to protect plants in the early spring. A guerrilla farmer in the Poconos puts up four posts, one at each end of a row. She uses them as a frame for clear polyethylene covering, creating a small greenhouse.

Growers in Zone Five sometimes harvest a spring crop by transplanting indoor-grown, two-month-old plants outdoors right after the last frost date. The naturally short days and long nights trigger the plants into flowering. (See Transplanting below, and the discussion of the photoperiod in section 3.)

If started after May 15, marijuana may not have time to reach its full size or flower. This problem mainly affects growers in Zone One and in mountainous areas. But even if the plants do not grow to full size or flower, you can still harvest a potent crop of preflowering tops, which may be almost as potent as ripe buds. The harvest is not as large as a crop of buds, but it is more than worth the effort.

3.5 Transplanting

Seedlings and young plants are transplanted after the last threat of frost. If the growing season in your area is less than five months, you may want to start the plants indoors, or in cold frames, transplanting when the weather permits. A 10-by-four foot cold frame can easily hold 60 two-month-old plants. The cold frame can be constructed with two-by-two's or branches gathered at the site. Cover the frame with a double layer of six- or eight-mil polyethylene plastic or similar material. Attach the plastic to the frame with tacks or staple-gun tacks. If the area is unprotected from the elements, slant the roof so that rain will run off. If the area is windy, place rocks or branches along the frame to add weight. Orient the cold frame to face the south.

In areas with a growing season of six months or more, plants will not necessarily get larger if they are started earlier than normal. Plants started at normal planting time catch up to the older plants by season's end. It serves no purpose to start plants before about March 21, the spring equinox.

Where there is no threat of frost (in Hawaii, southern Florida, and parts of Texas, Louisiana, and California), growers can raise a winter crop. Grow the plants for two or three months under artificial light. Plant get off to a faster start under artificial lights than natural light during the winter months. Move or transplant them before the beginning of March. Most strains will flower because of the short days (less than 12 hours of light) and fill out to well formed plants by the end of May when they are ripe.

For the normal summer crop, seedlings should be transplanted after the last threat of frost. The best time to transplant is on a rainy or cloudy day, which allows the plants to adjust to the new environment without the strain of intense sunlight. Plants grown in a cold frame or sunny window adjust more easily than plants grown under fluorescent lights. Plants grown under artificial light usually show evidence of shock when they are moved to sunlight. Near sea level they may lose some of their green color and appear pale or yellowed. At high altitudes, such as mile-high Denver, the leaves may actually burn, turn brown, and fall. Healthy plants usually recover quickly by adjusting the new growth to the changed conditions. However, plant can be conditioned to the new environment by being placed in a partially sunny area, preferably where they are shaded during the middle of the day and receive either morning or late-afternoon sunlight. The plants need about a week to adjust.

Seedlings grown in planting pellets for up to 10 days after germination can be placed directly in the soil. Peat pots should be scored with a knife so that the lateral roots can penetrate the pot more easily. Seedlings started in milk cartons or flower pots should be removed from the container so that the roots are disturbed as little as possible. Plan on using a pot size which is root-bound by the time that you transplant. (For the relationship between pot size and number of weeks, see Table 17.) To transplant, water the area to be transplanted and the plant. Then dig a hole a bit larger than the pot and loosen the surrounding and underlying soil. Place the plant in the hole, and pack the soil so that the stem base is at the same depth that it was growing at before. Firm the soil and water the area.

In areas where ripoffs are expected, such as parts of Hawaii and California, some guerrilla farmers transplant individual plants (one to each site) to sites which are widely spaced over the countryside. In this way they may lose some, but at least not all, of their plants to ripoffs.

Each plant (one to three months old) is transplanted to a cone-shaped hole, two to three feet deep by two feet across the top. This strategy is well-suited to areas with poor soil. Since much of the hole is taken up by rootbound soil, it is easy to gather enough topsoil and sand to fill the hole. The gathered soil should also be mixed with organic or slow-release fertilizers which provide ample N and P.


4.2 Weeding

Marijuana is a fast-growing annual whose survival depends on its ability to compete with other fast-growing weeds. At the end of each season, plants growing in a wild stand may cover the ground with thousands of seeds per square foot. Many of these are relocated by wind, runoff, and birds, and some are destroyed or die. Other never receive the conditions they need to germinate; and of those that do germinate, many die as seedling. The remaining plants compete with each other and with other weeds for the available light, nutrients, and water. Even so, wild stands may be as dense as forty plants per square foot. In order to survive the competition, Cannabis expends a great deal of its energy during the first two month growing a main shoot which is taller than the surrounding vegetation. Then it develops lateral branches which shades the shorter plants. With their source of energy - light - cut off, the shaded plants stop growing and often die.

When you cultivate - that is, eliminate weeds - the rate of germination and survival of your plants is increased enormously. Growers using clover, sheet composting, or mulch as ground cover can expect very little interference from weeds during seedling development. But plots of fertile, aerated, and cleared soil are open to colonization by a wide range of plants; so you may have to weed several times before the marijuana's dominance is assured.

When you weed, make sure not to pull out any weed seedlings which may have roots in the same area as the Cannabis roots. Instead, cut the weeds slightly below the surface with a clipper, scissors, or your fingernails. Weeds more than six inches away can be safely pulled. Leave them to dry right on the soil. As they dry and decay, they return the soil's nutrient to it.

Growers plagued with weeds can cover the soil with mulch, paper, or polyethylene sheets. One grower found that two computer sheets fit exactly between the rows. Another used torn drapes as a temporary ground cover.

Once Cannabis has established dominance over an area, the other weeds are not able to interfere with its growth. But if there is wide spacing between the plants, the weeds may have open space and start to grow rapidly. Keep these weeds clipped short if water or nutrients are scarce.

4.3 Watering

Marijuana requires an ample supply of water to live and grow. The actual quantities that it needs depend on the plant's size, the gardening techniques, type of soil, temperature, wind, humidity, and intensity of light. A vigorous plant may transpire several gallons of water a day during the hot summer months. If it receives less water then it need, it stops growing, wilts, and then dries out.


Marijuana germinates best in a moist soil. Within a week, it grows a taproot three or four inches long. By the end of the first month, the root system may stretch over an area a foot and a half in diameter and go more than one foot down. Until then, the soil should not be allowed to dry out. Plants which have germinated during warm, sunny weather may need to be watered until the roots have grown deep enough to reach sub-soil moisture. When the soil three inches below the surface feels dry, seedlings should be watered, preferably by using a watering can or the spray setting on a hose. Gently water the soil, making sure not to disturb the seedlings or the soil surrounding. The soil should be thoroughly saturated so the moisture percolates down, encouraging the roots to grow deep. If the surface is only lightly watered, the roots may grow near the surface, leading to water problems as the soil gets drier during the summer.

After the first month, Cannabis does best when the soil goes through alternating moist and dry periods. This alternation allows the lateral roots to come into contact with air. By the end of the growing season, the root system may penetrate the soil to a depth of six feet or more. As long as they are not blocked by solid rock or dense clay, the roots grow by following a trail of moisture. If the trail leads deep, the roots follow. The deeper layers of soil are less likely to dry out during hot, dry weather.

Older Plants

As a rule of thumb, Cannabis over a month old should be watered when the soil about six inches deep feels dry. But this rule provides only a rough indication that the plants need water, because there may be deeper sources of water that are not apparent. The most obvious indication of a problem is wilting. A more subtle one is slow growth during the (ordinarily fast-growing) vegetative stage.

Since you want to wet the lower layers, you should thoroughly saturate the soil. If the soil is completely saturated, it should hold water for a minimum of a week. Usually only two or three waterings a month are required by a garden that is completely dependent on irrigation.

The most efficient way to water is to let the water slowly seep into the soil, so that all the organic particles which hold the water are saturated. If the soil is very dry, and the water beads or runs off and is not absorbed, add household laundry detergent at the rate of one or two grams per gallon of water. It acts as a wetting agent, which breaks the surface tension. Once the soil is treated with a wetting agent, it usually absorbs water throughout the growing season.

In drier areas where corn. cotton, and other deep-rooted crops are irrigated, marijuana also requires an additional source of water. But in areas where there are patches of wild hemp or where deep-rooted crops grow by using available ground water, marijuana does not need to be watered, although additional water may increase its growth.

Box I
Water in General

Deep soil layers retain water much longer than the top layers. To encourage the development of a deep root system, saturate the ground when you water. The roots follow the moisture trail.

Water conditions also vary from field to field. For instance, many mid-western farmers plant along the banks of meandering streams. Even in dry areas, these plants have a natural source of water. Mountainous areas are usually well-drained and dry out before valleys do. Low-lying fields remain moist later, and are saturated by runoff from higher ground. In browned areas, farmers look for green spots which indicate underground streams, springs or runoff. Planters look for deserted wells or active watermains with leaks. Fields high in organic matter retain moisture longer than other fields, and mulching may cut water evaporation by 50 percent.

Watering Techniques

Gardeners may supply water by using a bucket, can, or water-hose. But growers with larger plots often rely on waterpumps to deliver river, lake, or well water to their gardens. Irrigation canals, drainage pipes and ditches, and water mains are sometimes convenient sources of water. The two most efficient methods of watering are the drip hose, which seeps water around the plant, and hand watering into an enclosed area around the plant's stem.

There are several kinds of drip hoses. Some have perforations every three to six inches along their length. These are useful when marijuana is planted in rows or large hills. Another kind is actually a kit, consisting of a main feeder hose and several side hoses two to four feet long. Each side hose has a metal bulb at the end which can be adjusted to regulate water flow. The bulb lies near the plant stem. A drip bottle was invented by a grower in the dry area of Nebraska who was only growing a few plants. He punched pinholes in the bottom of several one-gallon milk jugs and placed a jug near each plant. The jugs slowly watered the garden. Every few days, he refilled the jugs from a nearby irrigation ditch. As the plants grew larger, he placed more jugs around them. The drip method moistens the soil slowly, but does not flood it; so the soil and its nutrients are not washed away. Since this method allows you to decide exactly where the water goes you need not waste any on non-productive land.

Growers sometimes use elaborate setups, such as battery-electric, hand- or foot-powered, ram- or windmill-driven pumps. Foot-powered pumps are probably the most convenient for small plots. They are extremely lightweight (just a little heavier than a bicycle), inexpensive, easy to construct and disassemble, and virtually silent. Since you have much more power in your legs than in your arms, foot-powered pumps con do more work, and do it faster, than hand-powered pumps.

Electric pumps are relatively quiet and pump and enormous amount for their small size. But they require a source of electricity. They cannot be used unless there is a power line available, although there are car alternators available which produce 110-volt current.

Gasoline pumps and electric generators are heavy and noisy. Even with a muffler, they can be heard for miles in some country areas. They require a source of fuel, and often an elaborate setup, including rigid feed tubing, fuel tank, and platform. But once they are in place, the can deliver a tremendous amount of water. They are usually used by farmers growing large plots. Sometimes growers dig a hole in which they store and run the equipment. This setup helps muffle the sound and keeps the machinery in good working order.

Ram- and windmill-powered pumps use running-water and wind energy, respectively. They come in many sizes and are often used to fill water tanks for later use. They can also be used to generate electricity to run electric pumps. They require no fuel, are usually silent, and can be constructed inexpensively.

But some farmers have devised other methods for getting water to their plants.

A farmer growing near Tucson, Arizona, trucks water to her plants twice a week using a pickup truck and four 55-gallon barrels. She attaches a garden hose to her tanks, and siphons the water to her garden, 200 feet downhill.

Two foresighted farmers in Texas carried twenty 30-gallon plastic trash cans and lids to their garden. During the spring rains, they filled the containers from nearby gullies. By the end of the rainy season, the had collected enough water to carry them through the summer drought.

A homesteader in Oregon's dry eastern section dammed a gully by using and earth stabiliser, plastic, wood and cement, and pipe. During the winter his private reservoir filled.

Farmers near Atlanta tapped into a city water main. The pressure from the water main allowed them to pipe water uphill.

4.4 Thinning

If the soil is kept moist during germination, most of the viable seeds that you planted will germinate and the seedlings will soon start to crowd each other. This happens frequently when the plants grow on their own. Then they grow into a dense hedge-like mass dominated by a few plant. The dominant plants typically have long internodes and a long sturdy stem with little branching. The shorter, bushier plants are shaded by the taller ones and become stunted from the lack of light. By thinning, you give the plants that are left enough room to grow to their full potential, and you choose the ones that you think will grow to be the best for smoking. Leave the plants that have dense foliage, are branching, and, later in the season, the ones that are the most potent.

Thin the plants as soon as they begin to touch or crowd each other. This should be repeated as often as necessary. Seeds sown six inches apart in rows two feet wide require thinning several times during the season. But guerrilla farmers sometimes let the plants compete so that the garden looks more like a wild stand.

There are two methods used to thin: cutting the stem at the base so that the entire plant is destroyed, and cutting just the tops so that the plant's growth is thwarted, and the uncut plants shade it. The cut plants remain relatively inactive, and do not use much water or nutrients, but they do shade the ground and use otherwise wasted space.

4.5 Staking

Outdoor-grown plants rarely need staking. When the stem bends from the wind or rain, tiny tears in the structure develop. These are quickly mended by the plant: it grows new cells which increase the girth of the stem and make it stronger. But plants which are suffering from nutrient deficiencies or are top-heavy because of competition may need to be staked. Heavy rain sometimes cause the plants to fall over, especially if they have shallow root systems which cannot hold the added weight.

To stake, drive a sturdy rod six inches from the stem and deep enough into the ground to be able to give the plant support. Then tie the stem to the stake with wirer twists or string.

If the stem or the branch is cracked, pinched, or bent at the base, its position should be corrected and held firmly with a splint. The splint can be held with masking tape. In a few days the plant grows tissue to support the damaged area.

4.6 Pruning

Growers prune (clip or top) their plants to increase productivity, prevent detection, or to harvest early smoke. In the near future, new laws will decriminalize or legalize marijuana cultivation. These laws will probably limit legal cultivation either by the total gardening area or by the number of plants an individual or group may cultivate. Gardeners limited by space will maximize yield by cultivating a dense stand of tall, unclipped marijuana. Growers permitted to grow only a few plants will grow the largest, most productive plants possible. This is done by giving the plants the best possible growing conditions and a lot of space between plants to maximize light and minimize competition for water and nutrients.

Unpruned marijuana develops in one of three classic shapes, depending on variety. Many Mexican and Thai varieties develop into a tall, narrow bush no wider then three feet and shaped like a poplar tree. Colombian, Cambodian, Indian, and some south Mexican and Vietnamese varieties are Christmas-tree shaped. Some Moroccan and Afghani varieties have complex branching and naturally grow into small, dense bushes, about five feet tall. Marijuana usually grows to its full height by early September. Most of the marijuana plants you are likely to cultivate will grow to between eight and fifteen feet tall. Some Hawaiian and Thai varieties average between twelve and twenty feet tall.

Increasing Yield

When marijuana is clipped to increase the number of growing shoots, the total yield at season's end may not be increased. Provided that soil and water are not limiting to growth, each plant can reach a maximum size when given enough room. The more surface are the plant presents to light, the closer it will get to its maximum potential. Where the plants are grown with much space between them, clipped plants can yield more than unclipped plants, especially if the branches are spread out to maximize the light on the plant. When the plants are grown close together, the taller a plant is, the more sunlight it will receive, and hence the larger the possible yield.

Some growers prefer to harvest a top stem that is thick with buds (colas). The largest colas form on the main growing shoot of unclipped plants. When the growing shoot is clipped from a plant, the new shoots and leaves grow slower and smaller than the main shoot of an unpruned plant because the capacity for growth is spread out over several shoots. When a plant is clipped early in the season, most of the difference in lead and bud size is made up by harvest time.

Marijuana can be pruned at any time during the seedling or vegetative growth stage, but you should prune plants when they are young if you plan on harvesting growing shoots during the season. A seedling clipped anywhere from the fourth to sixth node will usually form at least six strong growing shoots that can be harvested during the third or fourth month. If these shoots are cut again while the plant is still young, marijuana often develops into a small, very compact, hedge-like bush.

Yield can be increased by spreading the plant's branches so that more light reaches the inner growth. Cannabis stems are bent most easily when they are still green and fleshy, nearer to the new growth, but the whole plant can be bent to form a gentle arch with the top of the main stem in a horizontal position. Within a few days the side branches along the top will begin to grow vertically, competing with the main stem. They will soon develop their own horizontal side branches. To bend a plant, tie the main stem loosely with a cloth or heavy string. Tie the other end of string to a heavy weight or anchor on the ground. Don't put too much pressure on the stem as this tears some of the roots and weakens the plant. You can bend the plant a little each day until the plant is in the desired position.

You may also increase yield by bending only the growing tip. This encourage the side branches to develop sooner than they naturally would. Only the flexible part (about the last foot) is bent. To bend the top, use stiff wire or wire twists used for plastic bags and wrapping vegetables. Fasten the other end of the wire lower in the stem to hold the tip in position.

A common mistake that cultivators make is pulling off the large leaves on the main stem (sun or fan leaves), when the plants are young. These leaves are removed by cultivators who believe that their removal will cause the undeveloped side shoots to grow. But fan leaves are net producers of sugar and energy, which are used by the side soots to begin growth. Rather than encouraging new growth, the removal of fan leaves slows growth. The plant will also be more susceptible to attacks from pests and predators.

When the plant is several weeks old and growing well, the difference between plants with their leaves removed and those left intact may not be large. The biggest difference can be seen when leaves are removed from branches just prior to, or during, flowering. The buds that form from leaf axils with leaves removed are noticeably smaller than those where the leaves have been left on the branch.


Cannabis can be detected from both the ground and the air. From the ground, marijuana is revealed by its familiar shape, unmistakable leaves, and odor. Tall plants are usually more conspicuous than shorter ones. From the air, stands may have a different color than the surrounding vegetation, especially where natural vegetation is not as lush as marijuana. Individual plants usually have a circular profile when viewed from above; this can be altered by bending or pruning the plant. Varieties which are naturally tall-growing may need to be cut several times during the season to keep them hidden.

Plants are sometimes cut back severely, to much as half their height when they get too tall, but this may damage the plant. A less drastic topping technique is to remove the opt foot of growth. Whenever new shoots get too tall they are clipped. But the plants should not be severely pruned late in the season when the growth rate has slowed (preflowering), because there will be fewer branches left on which buds can develop.

If you are trying to conceal plants behind a fence or wall, start bending or pruning the plants early, at about one month of age. By starting early and continuing to prune during the vegetative growth stage, you will train the plant to branch and fill up the area. If you wait until the plants are already tall, you may have to cut the plants back severely or clip shoots continuously.

4.7 Gardening Tips

Transplant Older Plants

A friend of ours was warned that his garden had been spotted by local authorities. Rather than cut down his four-month-old plants, he decided to transplant them. He dug the plants out, leaving a ball of soil about two feet square around the roots of each one. He wrapped each soil ball tightly in a plastic bag to transport it, and placed the plants in newly dug holes in a different spot. He kept the plants well-watered. After a few days, they recovered from transplant shock and started to grow once again. Transplanting large plants is not easy to do, but it could save a crop. The marijuana root system is not very extensive when the plants are in fertile soil with plenty of water; the tap root may only be six inches long on a ten-foot plant.

Wind Protection

Hemp Cannabis planted closely together has been used by farmers to form a windbreak to protect other crops. If you are growing in an especially windy area such as the Midwest, you may wish to plant a perimeter if tightly spaced Cannabis to protect your garden. Construct a rope and stick fence against the windbreak to hold the plants upright and prevent them from falling into the central garden. Simply keeping the plants clipped short is a simpler approach.

Inducing Flowering

Growers may wish to induce their plants to flower early, especially in the North, where the growing season is short. Plants in containers can be moved to a dark area for 12 hours of darkness or more per day. Black sheets of polyethylene film, dark plastic bags, and large appliance cartons can be used to provide periods of uninterrupted darkness. Use the dark treatment nightly until the plants are flowering (usually after one to two weeks of long-night treatments).

Winter and Spring Crops

In southern parts of the U.S., Hawaii and parts of California, you can grow more than one crop in a season. Greenhouses that stay above freezing can also be used for year-round growing. Plants started during the winter or early spring get naturally long nights and flower early, when they are relatively small, usually no more than four feet tall. Flowering can be postponed by breaking the long nights with short periods of light. This extends the vegetative growth period, yielding older, larger plants at flowering. Start breaking the night period with artificial light when the plant is about a month old. Continue the treatment until you want the plants to flowers. (See the discussion of photoperiod in section 3.)

Spring crops can be trimmed of buds when mature. The plant is left in the ground, and as the daylength increases, the plant will renew vegetative growth and flower once more in the fall. Plants can also be started in November or December indoors under lights and planted outdoors in February for harvest in April or May. The plants will grow faster under lights than they would outdoors under the weak winter sun. When they are placed outdoors, the long nights will induce flowering. By April the sunlight gets much stronger, perfect for flower development. Plants placed outdoors in February adjust easily to sunlight. Even so, they should be conditioned so that they do not suffer severe burn, as described in the Transplanting section in section 11.


Plants grown in areas where the weather is mild can survive winter when there are no heavy freezes. During the winter the plants will grow very slowly, but as soon as the weather warms, and the light gets more intense, the plants respond. This technique can also be used to obtain a second growth crop during Indian summers. The second growth is not as vigorous as the original, but is does increase the total harvest.

To prepare plants for rejuvenation, leave three or four pairs of lowers branches with leaves on the plant when you harvest. The leaves need not be large, but they must be green. Water and fertilize the plants. Within a few days the plants will show new growth.

The authors observed an outdoor container composed entirely of plants which survived a mild San Francisco Bay Area winter. These developed healthy second growth the following summer and flowered again in the fall. Some growers in Hawaii claim that their plants are three years old and that the plants have yielded as many as six crops of buds. Perennial marijuana plants also grow in Jamaica and Thailand.

Water Deprivation

Many cultivators begin to limit the amount of water their plants receive as soon as the flowers start to appear. Other growers give their plants as little water as possible after the middle of the plant's life. The plants are given small amounts of water only when they begin to wilt. (See section 9 on the reasons for stressing the plants.)

Under water stress many of the leaves may die and fall from the plant. Sometimes the plants appear "burned," and turn brown or gold. At harvest, water-stressed plants may only have buds left on them and these may have the color, resin, and harshness typical of Colombian grass. These plants yield less grass at season's end. Not only are they smaller overall, but many of the leaves will have fallen away.

Water stress can be difficult to control in areas with heavy summer rain. Water-stressed plants often make up for their smaller size by a raped burst of growth after a heavy rain. One method of control is to cover the ground with plastic sheets when it rains so that most of the water runs off.

Tacks and Nails

Some growers hammer nails or tacks into the stems of plants several weeks before harvest. Many growers use long thick nails; others prefer to use several half-inch-long tacks. The nails are usually placed at the base of the stem. This is supposed to "increase potency."

Stem Splitting

This is a popular way to stress used by cultivators in the United States. The stem is split (not cut) at the base to from a space through the stem. Growers place a rock, small piece of wood, an old Cannabis stem, or piece of opium (in Africa) in the split. Sometimes the wound is bound with cloth or plastic. We don't recommend this procedure, and advise you to be careful not to kill the plants and ruin the harvest.


Outdoor growers are well-advised to plant several varieties of marijuana, because some varieties adapt to their new environment better than others. Also, each variety (and to small extent, each plant) has its own bouquet. By planting several varieties, cultivators assure themselves a varied selection of smoking material.

In areas with short growing seasons, many tropical varieties do not have a chance to flower. But immature material from these varieties may be more potent than mature flowers of a plant grown from seed of lower-quality grass. For instance, compare a flowering Mexican with a Colombian that doesn't. The Colombian may be better because the difference in varieties is so great. On the other hand, the Mexican may be better because it is flowering and has reached its full potential.


It is well-known that certain plants may be antagonistic to other species of plants, and that there are also beneficial relationships between species. Cannabis is known not to grow well among spinach 222. Although tomatoes and tobacco have been recommended as crops to avoid when growing marijuana, because of pests and diseases that these plants may harbor 67, marijuana grows very well in healthy tomato patches. Growers have also commented on how well marijuana grows when planted with corn, sugarcane, and beets.


Outdoors, where it functions as part of an ecological system, marijuana is less susceptible to insect attacks than it is indoors. In an outdoor environment, insects are subject to the vagaries of the weather, food supply, and predators. And marijuana grows so fast that insects usually do little damage. Plants, plant eaters, and predators usually maintain an equilibrium which minimizes damage. But this balance is disturbed by tilling and gardening, and may take a while to re-establish itself.

The soil surrounding your plants may be teeming with insects, and it would be unnatural not to see some on your plants. Most insects do not eat marijuana. The few that do are the food which helps to keep a small population of their predators alive. Insects in the garden need to be controlled only when there is a real threat of damage.

Marijuana is most vulnerable in its early stages. After the plant increases production of the cannabinoids and resins at the eighth or ninth week, most insects are repelled. When the plants are small, an occasional munch affects a relatively larger part of the plant. That same bite affects a relatively smaller part when the plant is larger.

The insects that infect marijuana indoors - aphids, mealy bugs, mites, and whiteflies - do best in humid conditions with constantly warm temperatures. Outdoors they rarely inflict much damage on marijuana. The pests that are most likely to damage marijuana are leafhoppers, treehoppers, cucumber beetles, thrips, flea beetles, several kinds of caterpillars, snails, and slugs. The younger the plants are, the more susceptible they are to attack. Your prime goal is to protect the plants during the first two vulnerable months. You need to keep the pest population low, so that the damage is relatively light. The pests don't have to be eliminated, only kept under control.

There are many ways to keep pests from damaging your crops. These fall into one or more of several categories: biological control; capture traps and barriers; home remedies; and chemical insecticides.

5.2 Biological Control

The theory behind biological controls is that methods for control of pests can be found within nature. These methods are safer to humans and less damaging to the environment than commercial insecticides. Gardeners have many forms of biological control at their disposal, including companion planting, use of predators, and sprays made from plant extracts or ground-up insects.

Companion Planting

Some plants, including marijuana in its later stages, produce resins or essences which repel or kill plant pests. Some of them are general repellents that affect a broad range of plant pests; others affect specific species. Generally, the heavily scented plants, such as spices, mints, and other herbs, are most likely to have these qualities.

Some of the more familiar plants used to protect gardens are the Alliums, or onion family, with garlic, chives, green onions, and other oniony-type plants as members. This group repels a broad range of plant pests such as aphids, spider mites, flea beetles, potato bugs, bean beetles, and many other insects, as well as rabbits and some deer. They are easily planted around the garden or between the marijuana plants. Just plant onion bulbs or the cloves from a garlic bulb so that the top of the bulb is about one inch deep. One garlic bulb yields quite a few cloves; so a large garden requires only a few bulbs.

Geraniums are reputed to repel leafhoppers and many kinds of beetles. These plants prefer a dry soil, thrive in full light, and usually grow two feet tall. Geraniums should be interspersed with the marijuana, or potted geraniums can be set out if problems develop. Tansy (Tanacetum vulgare) is a tall, fragrant, woody perennial which grows five feet tall. It protects against cut-worms, beetles, cucumber beetles, and other eaters and borers.

Mints repel many insects and are sometimes used as mouse repellents. They are especially useful for the control of the flea beetle. They thrive in semi-shaded areas with rich soil.

Marigolds can be planted to eliminate nematodes. They are fast-growing annual plants which flower profusely. They come in many varieties, ranging in height from six to 30 inches. They grow in a wide range of soils and do best in the sun. The scented varieties - usually nonhybrids - offer the most protection.

All companion plants must be planted close to the plants to be protected, since their repellent qualities spread only a short distance beyond their circumference. They are effective when they are planted before the damage is apparent, and offer long-tern protection. They are used when a pest is expected. For instance, growers in the San Francisco Bay Area expect rose leafhoppers to attack their plants. Since geraniums grow in the area as perennial plants, some growers plant them permanently in the garden. As the geraniums develop into small bushes, the hoppers leave, never to return.


Many of the insects in your garden are called beneficials, because they perform a useful service in the garden. Some of them eat decaying matter; others help in the pollination process; and some pry on insects which damage crops. Almost everyone is familiar with the ladybug, which eats aphids and insect eggs and has a voracious appetite. They are available commercially by the pint. The praying mantis eats slow-moving insects. When it first hatches, it starts out on aphids and mites. But as it grows larger, it eats bigger insects and worms. Mantis-egg cases are foam-like, straw-colored masses which contain 100 to 300 eggs. These cases are sold commercially but can also be found in the late fall in bushy areas. Another insect which is sold commercially as a plant protector is the green or brown lacewing. It has golden eyes, looks fragile, and flies erratically. But in their larval state, lacewings eat thrips, mites, caterpillar eggs, scale, leafhopper nymphs, aphids, and mealybugs. The trichogamma wasp is an egg parasite which lays its eggs in the eggs of over 200 species of insects, including many moths and butterflies which hatch into worm pests. Cryptolaemus is used to destroy mealybugs. Adults are released when mealybugs appear in the spring. They seek out the mealybug colonies and lay their eggs. When the eggs hatch the larvae wander around the infested area and eat the young mealybugs.

The use of commercially bred or gathered predators is most feasible in large gardens or fields. The insects may not have much effect on small gardens, since they wander off to find food and may never return. Try to buy from manufacturers who intentionally do not feed their product before shipping. Hungry predators are more likely to stay and eat the pests.

Insects are just one groups of predators. Birds such as purple martins, robins, blue jays, chickadees, and even starlings and English sparrows eat large quantities of insects and other small pests. They can be attracted to the garden by placing a feeder, bird houses, and water in the area. When plants get larger, some gardeners let chickens, ducks, or geese run through the garden. In a short time, they pick it clean of pests and weeds. Reptiles and amphibians, including frogs, toads, snakes, lizards, and turtles, all eat garden pests and should be encouraged to make a home in the garden.

Homemade Repellents and Insecticides

Another way to control garden pests is to make sprays from plants which repel insects by using a juicer or blender or by baking a tea. Ingredients can be found in most kitchens. Chile pepper, garlic, coffee, horseradish, radish, geranium, and tobacco are the usual mainstays of herbal sprays, although most strong-smelling herbs and spices have some repellent qualities. Many gardeners experiment to see what works in their garden. For instance, if an insect which bother marijuana stays clear of a nearby weed, a tea or blended spray made form that plant may control the pest. But try it on only one plant (or part of a plant) first, because the spray may also be harmful to the marijuana.

Garlic is probably the most popular ingredient for general-purpose sprays made from kitchen ingredients. A typical formula is to soak three ounces of chopped or minced garlic in a covered container of mineral oil for a day. Then, slowly add a pint of lukewarm water in which a quarter ounce of real soap (Ivory will do) has been dissolved. Stir and let stand several hours, than strain. Use as a concentrate, adding between 20 to 100 parts water to one part concentrate.

Other recipes call for boiling the garlic or for grinding or juicing it. Some brewers add other spices to the basic formula. One recipe calls for one clove garlic, three cayenne peppers, one onion, a quarts ounce of soap, and sufficient water to blend. Let it sit for three or four days before using, and use one part concentrate to 20 parts water. Homemade tobacco teas are sometimes used as insect sprays. Use one cigarette in a quart of water. Let it brew 24 hours before using.

Snails and slugs are attracted by yeast solutions, which are easily prepared from cooking yeast, sugar, and water. This is also why gardeners have success trapping these leaf munchers in bowls of stale beer. Place deep-sided containers at the soil level. The pests slide in and drown.

Gardeners should not overlook handpicking as a viable method of pest control. The foot or a quick thumb and forefinger can eliminate large numbers of pests and can keep a small garden pest-free. Collect the bugs and drop them in a tin can with some alcohol to kill them. Early morning is the best time to collect pests, since they are slower-moving until the sun warms them.

Snails, slugs, earwigs, and some other insects gather in cool, moist areas during the heat of the day. By providing just such a space in a garden, many of these pests can be located and destroyed. Place pieces of cardboard or boards around the garden; look under them each day.

Home Remedies

Gardeners and farmers have discovered and invented ingenious ways to control insects without harming the environment. Some of the more popular ones are listed here, but there are many more, each suited to a particular situation.

Soap and water is an effective control measure for mealybugs, mites, leafhoppers (nymph stage), leaf miners, and aphids. Simply wash the plants thoroughly with a solution of two tablespoons of soap dissolved in a gallon of water. Rinse the soap off thoroughly. (Some growers feel that the addition of kerosene or alcohol makes the solution more effective, but these can harm the plants and dissolve THC.) This treatment does not eliminate all of the pests, and may need to be repeated weekly, but it does keep them under control.

Sprays are sometimes made from healthy insects, which are caught, ground up, and then sprayed back onto the plants. When the pests come in contact with the spray, they become infected with the pathogen and get sick. This method is very effective, and is considered safe, but it is not easy to capture sick insects. A variation in this technique was described in the October 1976 Organic Gardening and Farming Magazine, in which a spray was made from healthy insects. In a followup article in the May 1977 issue, the authors theorized that any population of insects contains pathogens. If enough insects are collected, some of them are sure to be sick, and they contain enough germs to spread the disease. To make an insect spray, capture about a hundred pests. (Make sure not to include any beneficial insects or the spray may also work against them.) Using a blender, mix them with a cup of spring water, strain, and dilute with enough water to spray your garden.

Whenever making or storing sprays, use a glass container. Metal or plastic ones may react with the chemicals that the liquids contain.

Another home remedy for the control of mites and aphids is a mixture consisting of a half cup of milk in four cups of wheat flour, added to five gallons of water. When it is sprayed on the undersides of the leaves, it suffocates the insects and then flakes off as it dries.

Some growers use mulches to control insects. Cedar chips repel beetles, moths, mites, and mealybugs. Aluminium foil is used for aphid and thrip control on small plants; the reflected light disorients them and they do not land on the plants. A sprinkling of cream of tartar eliminates ants, and boric acid kills roaches. Sulfur powders, available at nurseries, are used to control mites and fungus infections.

Organic Insecticides

Pyrethrum, rotenone, and ryania are effective insecticides which come as powders (dusts) or sprays. They are concentrated form of naturally occurring plant substances, and are considered harmless to warm-blooded animals when used as directed.

Ryania, which is found in the roots of a tropical shrub, is most effective against chewing insects, worms, and larvae, which it incapacitates, rather than kills.

Rotenone is a general-purpose insecticide with little residual effect; that is, it breaks down soon after application, and is therefore one of the safest insecticides. Two or three dustings during the seedling stages afford protection against most insects and bugs.

Pyrethrum is one of the most powerful natural insecticides, and is effective against a wide range of pests. It is also relatively nontoxic to bees and ladybugs. Pyrethrums are found in the pyrethrum plant as well as in chrysanthemums. They are non-persistent, and in small doses may make the insects sick without killing them. These insecticides are available at many nurseries and may provide the surest, easiest form of protection against serious insect attack.

Barriers and Traps

In gardens and small farms, insects and other pests are sometimes controlled by the use of traps and barriers that prevent them from reaching the marijuana. When the plant are young, they can be protected from cutworms, caterpillars, snails, and slugs by a collar that is buried an inch into the ground and is six inches high. Some growers face it with aluminium foil, which many insects seem to dislike. One ingenious grower painted collars with molasses to capture the crawlers. She also caught a significant number of leafhoppers. Commercial stickums such as Tanglefoot can also be used to trap insects.

Snails, slugs, and some crawling insects are repelled by a border perimeter of lime, potash (wood ash), sulfur, sharp sand, or cinders. Place a thin layer, six inches wide, around the perimeter of the garden, or around each plant. Flea beetles and some other flying insects are repelled by wood ashes dusted on the leaves. The powders are water-soluble; so they should be replaced after a heavy rain. Crawling pests sometimes have a hard time reaching plants grown in containers or raised beds.

Flying insects, such as leaf and treehoppers, can be prevented from getting to plants by barriers made from cheesecloth. Other growers place cardboard sticky with glue between plants, and then shake the plants. The cardboard catches a good proportion of them. One innovative grower in Palo Alto, California, placed a furniture crate, with the top cut off and with Tanglefoot spread on the inside, around each of his six plants. He said that by shaking the plants, he eliminated leafhoppers in four days.

5.3 Chemical Insecticides

Insecticides were developed as an easy way to control pests. They have an immediate dramatic effect, but the long-range damage that they do to the entire ecological system is sometimes overlooked. The chlorinated hydrocarbons, such as DDT, DDC, Aldrin, Kelthane, and Dieldrin, were the most dangerous commercial insecticides. They affect warm-blooded animals and are no longer available. (In no case should any of these by used.)

Diazinon, Sevin, and Malathion are three insecticides which are often soil in nurseries to protect vegetable crops. They are considered safe for warm-blooded animals and have a limited residual effect, since they break down in a few days. But these insecticides are not too selective and may kill beneficials as well as pests. Sevin is the most toxic and kills the widest range of insects, including bees.

These chemicals come as sprays, powders, and baits, formulated for specific pests. They should be used only when an intolerable situation has developed. Plants should be harvested only after the required safety period has passed since application. This period is from two to 35 days, and is specifically listed on all insecticides that can be safely used. Insecticides should be used and handled carefully, following instructions, wearing protective clothing, with no children or pets around. It is advisable to use a mask when applying dusts and to work upwind.

5.4 Common Pests

Cucumber Beetles

Cucumber beetles are about a quarter-inch long and look a lot like ladybugs. There are several species of cucumber beetles. The striped beetle is found east of the Rocky Mountains. It is yellow, has two or three black stripes running down its back, and has a black head. The spotted cucumber beetle has a yellow-green back with 11 or 12 black spots and a black head. There are related species, such as the banded cucumber beetle, throughout the United States. The larvae of all varieties are white, turning brownish at the ends, slender, about one-third inch long.

Cucumber beetles do the most damage in the early spring, when the adults come out of hibernation and begin to eat the new growth and leaves. These leaf-eating adults damage young marijuana, especially when there is a scarcity of other food. They also transmit bacterial diseases and viruses to the plants. Within a few weeks after they come out of hibernation, they lay their eggs at the base of plant roots. The larvae of the striped cucumber beetle feed only on melon- and cucumber-type plant roots. The spotted-beetle larvae are fond of corn, and are known as the "Southern cornroot worm" in some places.

The best way to prevent cucumber-beetle attacks is to keep the areas that you plant isolated from corn and melon plantings. Heavy mulching or tilling destroys the pests when they are hibernating. Late plantings minimize damage inflicted by cucumber beetles.

Cucumber beetles can be controlled by use of Rotenone or Malathion. Dust several times during seedling growth. These beetles are also prey to many insects, including the common garden soldier beetle, predator flies, wasps, and nematodes. Hand picking is also an effective control for cucumber beetles.


Thrips are slender, yellow or brownish, winged insects about 1/25 inch long. They have fragile wings which keep them aloft while they are blown by the wind. Thrips have a cone-shaped mouthpart, which they use to cut stems in order to suck plant juices. The larvae look like adults, but are smaller and wingless. Most thrips feed on a range of plants, especially onion and other bulbs, and marijuana is at most a marginal part of their diet. A well-cultivated marijuana plant can outgrow and damage that thrips are likely to inflict.

Thrips hibernate in plant debris during the winter and begin sucking in early spring. They lay eggs during warm weather, and can produce a new generation every two weeks. Since thrips eat a varied diet, keeping the garden area clear of weeds is an effective control. Thrips can also be controlled by turning debris under, so that their nesting sites are destroyed.

Thrips can be controlled by use of tobacco sprays. Rotenone, or Malathion. Aluminium-foil mulches are effective thrip repellents. The light reflected from the foil confuses their sense of direction.

Flea Beetles

There are many species of flea beetles. The adults range in size between one-twentieth and one-fifth of an inch, and are usually black or metallic green or blue. They are called flea beetles because they use their enlarged hind legs to jump like fleas when disturbed. Many flea beetles are host-specific, and probably only a few species munch on marijuana.

Flea beetles hibernate in plant debris. By ploughing the debris under, their hibernation places are eliminated, and there should be few pests the following spring. Flea beetles are repelled by a mixture of equal parts of wood ashes and limestone sprinkled on foliage every few days. Containers of the mixture may also by placed around the plants. Garlic sprays also repel flea beetles. The chemical poisons used specifically for flea beetles are stomach poisons, which break down slowly and may not be safe to inhale. Home remedies are best for flea beetles.

5.5 Vertebrate Pests

Mammals Until it develops a hard fibrous main stem, usually at about two months, the young marijuana plant attracts rodents, including mice, rabbits, moles, squirrels, groundhogs, and rats, as well as raccoons. Cats are probably the best means of rodent control. They stalk small prey, go after any movement, and are active at night, when most of these animals forage. Young plants are often protected from rodents by placing a coffee can with top and bottom removed around each plant. When the plants get bigger, they can be protected from rabbits and other animals with a wire fence three feet in height. A double layer of one-inch chicken wire is most effective. But many animals can climb or burrow; so more ingenious methods are needed to protect the plants. Rodents, especially moles, are repulsed by castor beans and castor oil. A formula that gardeners sometimes use is two parts castor oil, one part detergent, mixed to a consistency of shaving cream in a blender. Use a tablespoon of concentrate per gallon of water. Spray or mist the solution on the plants.

Rabbits shy away from blood, bloodmeal, and tankage. To use, sprinkle the powder around the perimeter of the plot in a band about a foot wide. They can also be mixed into a concentrated solution and applied as a spray. However, the small of blood may attract mongoose or other predators, which dig up the garden in search of flesh. Noise from radios, chimes, and bells deter some animals, and human smalls such as hair and urine may also deter some animals. In dry areas, a half-filled bucket of water is an effective rodent trap. The animals fall in and drown.

Deer seem to go out of their way to munch on tender marijuana leaves, but generally don't bother marijuana after it has grown for a few months. Gardeners and farmers use many ingenious techniques to keep them away from crops. Sturdy fences are the best deterrent. The fences should be about 10 feet high: the bottom five feet should be made up of single strands of wire string at two-foot intervals. The wire strands prevent deer from jumping the fence. Some growers use fresh blood, dried blood, or bloodmeal to deter them, placing it in either powder or liquid form around the perimeter of the garden. Other growers claim that human hair, or manure from predators such as wolves, bears, lions, and even dogs, keeps them out. Lion urine (glans extract) is available commercially, and is said to be an effective deterrent against many animals.


On the whole, birds are beneficial, rather than harmful, in the garden. Most of the common species, including English sparrows, robins, swallows, wrens, finches, bluejays, bluebirds, and starlings, eat insects and other garden pests as a substantial portion of their diet. The only time that birds may be harmful is during planting, when they sometimes feed on the planted seed. The main culprits seem to be starlings, sparrows, and crows. They can be kept off the planted areas physically, by means of plastic netting or fencing, which is sold commercially for the purpose, or by using scarecrows, aluminium strips, or noise makers. Once the plants have germinated, birds are no longer a threat and should be encouraged to nest in the area, since they are an ideal biological control for plant pests.
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