"Marijuana : The Plant"Marijuana Grower's Handbook[Indoor/Greenhouse Edition] Ed Rosenthal ------------------------------------------------------------------------ It is recommended that you buy the book that these files are taken from. Many charts and some chapters have been omitted. Besides, Ed might need the money. ------------------------------------------------------------------------ Cannabis probably evolved in the Himalayan foothills, but its origins are clouded by the plant's early symbiotic relationship with humans. It has been grown for three products - the seeds, which are used as a grainlike food and animal feed and for oil; its fiber, which is used for cloth and rope; and its resin, which is used medically and recreationally since it contains the group of psychoactive substances collectively known as Tetra-hydrocannibinol, usually referred to as THC. Plants grown for seed or fiber are usually referred to as hemp and contain small amounts of THC. Plants grown for THC and for the resin are referred to as marijuana. Use of cannabis and its products spread quickly throughout the world. Marijuana is now cultivated in climates ranging from the Arctic to the equator. Cannabis has been evolving for hundreds of thousands of generations on its own and through informal breeding programs by farmers. A diverse group
of varieties has evolved or been developed as a result of breeders' attempts
to create a plant that is efficient at producing the desired product, which
flourishes under particular environmental conditions. Cannabis easily escapes
from cultivation and goes "wild." For instance, in the American midwest,
stands of hemp "weed" remain from the 1940's plantings. These plants adapt
on a population level to the particular environmental conditions that the
plants face; the stand's genetic pool, and thus the plants' characteristics,
evolve over a number of generations. Varieties differ in growth characteristics
such as height, width, branching traits, leaf size, leaf shape, flowering
time, yield, potency, taste, type of hig, and aroma. For the most part,
potency is a factor of genetics. Some plants have the genetic potential
of producing high grade marijuana and others do not. The goal of the cultivator
is to allow the high THC plants to reach their full potential. Marijuana
is a fast growing annual plant, although some varieties in some warm areas
overwinter. It does best in a well-drained medium, high in fertility. It
requires long periods of unobstructed bright light daily. Marijuana is
usually dioecious; plants are either male or female, although some varieties
are monoecious - they have male and female flowers on the same plant.
Marijuana's annual
cycle begins with germination in the early spring. The plant grows vigorously
for several months. The plant begins to flower in the late summer or early
fall and sets seed by late fall. The seeds drop as the plant dies as a
result of changes in the weather. Indoors, the grower has complete control
of the environment. The cultivator determines when the plants are to be
started, when they will flower, whether they are to produce seed and even
if they are to bear a second harvest.
"Choosing A Variety"Gardeners can grow a garden with only one or two varieties or a potpourri. Each has its advantages. Commercial growers usually prefer homogenous gardens because the plants tatse the same and mature at the same time. These growers usually choose fast maturing plants so that there is a quick turnaround. Commercial growers often use clones or cuttings from one plant so that the garden is genetically idential; the clones have exactly the same growth habits and potency.Homegrowers are usually more concerned with quality than with fast maturity. Most often, they grow mixed groups of plants so they have a selection of potency, quality of the high, and taste. Heterogeneous gardens take longer to mature and have a lower yield than homogenous gardens. They take more care, too, because the plants grow at different rates, have different shapes and require varying amounts of space. The plants require individual care. Marijuana grown in the United States is usually one of two main types: inidica or sativa. Indica plants originated in the Hindu-Kush valleys in central Asia, which is located between the 25-35 latitudes. The weather there is changeable. One year there may be drought, the next it might be cloudy, wet, rainy or sunny. For the population to survive, the plant group needs to have individuals which survive and thrive under different conditions. Thus, in any season, no matter what the weather, some plants will do well and some will do poorly. Indica was probably developed by hash users for resin content, not for flower smoking. The resin was removed from the plant. An indication of indica's development is the seeds, which remain enclosed and stick to the resin. Since they are very hrd to disconnect from the plant, they require human help. Wild plants readily drop seeds once they mature. Plants from the same line from equatorial areas are usually fairly uniform. These include Colombians and central Africans. Plants from higher latitudes of the same line sometimes have very different characteristics. These include Southern Africans, Northern Mexicans, and indicas. The plants look different from each other and have different maturities and potency. The ratio of THC (the ingredient which is psychoactive) to CBD (its precursor, which often leaves the smoker feeling disoriented, sleepy, drugged or confused) also varies. High latitude sativas have the same general characteristics: they tend to mature early, have compact short branches and wide, short leaves which are dark green, sometimes tinged purple. Indica buds are usually tight, heavy, wide and thick rather than long. They smell "stinky", "skunky", or "pungent" and their smoke is thick - a small toke can induce coughing. The best indicas have a relaxing "social high" which allow one to sense and feel the environment but do not lead to thinking about or analyzing the experience. Cannabis sativa plants are found throughout the world. Potent varieties such as Colombian, Panamanian, Mexican, Nigerian, Congolese, Indian and Thai are found in equatorial zones. These plants require a long time to mature and ordinarily grow in areas where they have a long season. They are usually very potent, containing large quanities of THC and virtually no CBD. They have long, medium-thick buds when they are grown in full equatorial sun, but under artificial light or even under the temperate sun, the buds tend to run (not fill out completely). The buds usually smell sweet or tangy and the smoke is smooth, sometimes deceptively so. The THC to CBD ratio of sativa plants gets lower as the plants are found further from the equator. Jamaican and Central Mexican varieties are found at the 15-20th latitudes. At the 30th latitude, varieties such as Southern African and Northern Mexican are variable and may contain equal amounts of THC and CBD, giving the smoker and buzzy, confusing high. These plants are used mostly for hybridizing. Plants found above the 30th latitude usually have low levels of THC, with high levels of CBD and are considered hemp. If indica and sativa varieties are considered opposite ends of a spectrum, most plants fall in between the spectrum. Because of marijuana and hemp's long symbiotic relationship with humans, seeds are constantly procured or traded so that virtually all populations have been mixed with foreign plants at one time or another. Even in traditional marijuana-growing countries, the marijuana is often the result of several cross lines. Jamaican ganja, for example, is probably the result of crosses between hemp, which the English cultivated for rope, and Indian ganja, which arrived with the Indian immigrants who came to the country. The term for marijuana in Jamaic in ganja, the same as in India. The traditional Jamaican term for the best weed is Kali, named for the Indian killer goddess. "Growth and Flowering"The cannabis plant regulates its growth and flowering stages by measuring the changes in the number of hours of uniterrupted darkness to determine when to flower. The plant produces a hormone (phytochrome) begining at germination. When this chemical builds up to a critical level, the plant changes its mode from vegetative growth to flowering. This chemical is destroyed in the presence of even a few moments of light. During the late spring and early summer there are many more hours of light than darkness and the hormone does not build up to a critical level. However, as the days grow shorter and there are longer periods of uniterrupted darkness, the hormone builds up to a critical level. Flowering occurs at different times with different varieties as a result of the adaptation of the varieties to the environment. Varieties from the 30th latitude grow in an area with a temperate climate and fairly early fall. These plants usually trigger in July or August and are ready to harvest in September or October. Southern African varieties often flower with as little as 8 or 9 hours of darkness/15 to 16 hours of light. Other 30th latitude varieties including most indicas flower when the darkness cycle lasts a minimum of 9 to 10 hours. Jamaican and some Southeast Asian varieties will trigger at 11 hours of darkness and ripen during September or October. Equatorial varieties trigger at 12 hours or more of darkness. This means that they will not start flowering before late September or early October and will not mature until late November or early December. Of course, indoors the plants' growth stage can be regulated with the flick of a switch. Nevertheless, the plants respond to the artificial light cycle in the same way that they do to the natural seasonal cycles. The potency of the plant is related to its maturity rather than chronological age. Genetically identical 3 month and 6 month-old plants which have mature flowers have the same potency. Starting from seed, a six month old plant flowers slightly faster and fills out more than a 3 month old plant."Choosing a Space"Almost any area can be converted to a growing space. Attics, basements, spare rooms, alcoves and even shelves can be used. Metal shacks, garages and greenhouses are ideal areas. All spaces must be located in an area inaccessible to visitors and invisible from the street. The ideal area is at least 6 feet high, with a minimum of 50 square feet, an area about 7 feet by 7 feet. A single 1,000 watt metal halide or sodium vapor lamp, the most efficient means of illuminating a garden, covers an area this size. Gardeners who have smaller spaces, at least one foot wide and several feet long, can use fluorescent tubes, 400 watt metal halides, or sodium vapor lamps. Gardeners who do not have a space even this large to spare can use smaller areas (See part 17 - "Novel Gardens"). Usually, large gardens are more efficient than small ones. The space does not require windows or outside ventilation, but it is easier to set up a space if it has one or the other. Larger growing areas need adequate ventilation so that heat, oxygen, and moisture levels can be controlled. Greenhouses usually have vents and fans built in. Provisions for ventilation must be made for lamp-lit enclosed areas. Heat and moisture buildup can be extraordinary. During the winter in most areas, the heat is easily dissipated; however, the heat buildup is harder to deal with in hot weather. Adequate ventilation or air coolers are the answer."Preparing the Space"The space is the future home and environment of the plants. It should be cleaned of any residue or debris which might house insects, parasites or diseases. If it has been contaminated with plant pests it can be sprayed or wiped down with a 5% bleach solution which kills most organisms. The room must be well-venitalted when this operation is going on. The room will be subject to high humidity so any materials such as clothing which might be damaged by moisture are removed. Since the plants will be watered, and water may be spilled, the floors and any other areas that may be water damaged should be covered with linoleum or plastic. High grade 6 or 8 mil polyethylene drop cloths or vinyl tarps protect a floor well. The plastic should be sealed with tape so that no water seeps to the floor. The amount of light delivered to the plant rises dramatically when the space is enclosed by reflective material. Some good reflective materials are flat white paint, aluminum foil (the dull side so that the light is diffused), white cardboard, plywood painted white, white polyethylene, silvered mylar, gift wrap, white cloth, or silvered plastic such as Astrolon. Mterials can be taped or tacked onto the walls, or hung as curtains. All areas of the space should be covered with reflective material. The walls, ceiling and floors are all capable of reflecting light and should be covered with reflective material such as aluminum foil. It is easiest to run the material vertically rather than horizontally. Experienced growers find it convenient to use the wide, heavy-duty aluminum foil or insulating foil (sold in wide rolls) in areas which will not be disturbed and plastic or cloth curtains where the material will be moved. Windows can be covered with opaque material if a bright light emanating from the window would draw suspicion. If the window does not draw suspicion and allows bright light into the room, it should be covered with a translucent material such as rice paper, lace curtains, or aquarium crystal paint. Garages, metal buildings, or attics can be converted to lighthouses by replacing the roof with fiberglass greenhouse material such as Filon. These translucent panels permit almost all the light to pass through but diffuse it so that there is no visible image passing out while there is an even distribution of light coming in. A space with a translucent roof needs no artificial lighting in the summer and only supplemental lighting during the other seasons. Overhead light entering from askylight or large window is very helpful. Light is utilized best if it is diffused. Concrete and other cold floors should be covered with insulating material such as foam carpet lining, styrofoam sheeting, wood planks or wooden palettes so that the plant containers and the roots are kept from getting cold. "Plant Size and Spacing"Marijuana varieties differ not only in their growth rate, but also in their potential size. The grower also plays a role in determining the size of the plants because the plants can be induced to flower at any age or size just by regulating the number of hours of uninterrupted darkness that the plants receive.Growers have different ideas about how much space each plant needs. The closer the plants are spaced, the less room the individual plant has to grow. Some growers use only a few plants in a space, and they grow the plants in large containers. Other growers prefer to fill the space with smaller plants. Either method works, but a garden with smaller plants which fills the space mroe completely probably yields more in less time. The total vegetative growth in a room containing many small sized plants is greater than a room containing only a few plants. Since each plant is smaller, it needs less time to grow to its desired size. Remember that the gardener is interested in a crop of beautiful buds, not beautiful plants. The amount of space a plant requires depends on the height the plants are to grow. A plant growing 10 feet high is going to be wider than a 4 foot plant. The width of the plant also depends on cultivation practices. Plants which are pruned grow wider than unpruned plants. The different growth characteristics of the plants also affect the space required by each plant. In 1- or 2-light gardens, where the plants are to grow no higher than 6 feet, plants are given between 1 and 9 square feet of space. In a high greenhouse lit by natural light, where the plants grow 10-12 feet high, the plants may be given as much as 80 to 100 square feet. "Planting Mixes"One of the first books written on indoor growing suggested that the entire floor of a grow room be filled with soil. This method is effective but unfeasible for most cultivators. Still, the growers have a wide choice of growing mediums and techniques; they may choose between growing in soil or using a hydroponic method.Most growers prefer to cultivate their plants in containers filled with soil, commercial mixes, or their own recipe of soil, fertilizers, and soil conditioners. These mixes vary quite a bit in their content, nutrient values, texture, pH, and water-holding capacity. Potting soil is composed of topsoil, which is a natural outdoor composite high in nutrients. It is the top layer of soil, containing large amounts of organic material such as humus and compost as well as minerals and clays. Topsoil is usually lightened up so that it does not pack. This is done by using sand, vermiculite, perlite, peat moss and/or gravel. Potting soil tends to be very heavy, smell earthy and have a rich dark color. It can supply most of the nutrients that a plant needs for the first couple of months. Commercial potting mixes are composites manufactured from ingredients such as bark or wood fiber, composts, or soil conditioners such as vermiculite, perlite, and peat moss. They are designed to support growth of houseplants by holding adequate amounts of water and nutrients and releasing them slowly. Potting mixes tend to be low in nutrients and often require fertilization from the outset. Many of them may be considered hydroponic mixes because the nutrients are supplied by the gardener in a water solution on a regular basis. Texture of the potting mix is the most important consideration for containerized plants. The mixture should drain well and allow air to enter empty spaces so that the roots can breathe oxygen. Mixes which are too fine may become soggy or stick together, preventing the roots from obtaining the required oxygen. A soggy condition also promotes the growth of anaerobic bacteria which release acids that eventually harm the roots. A moist potting mix with good texture should form a clump if it is squeezed in a fist; then with a slight poke the clod should break up. If the clod stays together, soil conditioners are required to loosen it up. Vermiculite, perlite or pea-sized styrofoam chips will serve the purpose. Some growers prefer to make their own mixes. These can be made from soil, soil conditioners, and fertilizers. Plants grown in soil do not grow as quickly as those in hydroponic mixes. However, many growers prefer soil for aesthetic reasons. Good potting mixes can be made from topsoil fairly easy. Usually it is easier to buy topsoil than to use unpasteurized topsoil which contains weed seeds, insects and disease organisms. Outdoors, these organisms are kept in check, for the most part, by the forces of nature. Bringing them indoors, however, is like bringing them into an incubator, where many of their natural enemies are not around to take care of them. Soil can be sterilized using a 5% bleach solution poured through the medium or by being steamed for 20 minutes. Probably the easiest way to sterilize soil is to use a microwave. It is heated until it is steaming, about 5 minutes for a gallon or more. Potting soils and potting mixes vary tremendously in composition, pH and fertility. Most mixes contain only small amounts of soil. If a package is marked "potting soil", it is usually made mostly from topsoil. If the soil clumps up it should be loosened using sand, perlite or styrofoam. One part amendment is used to 2-3 parts soil. Additives listen in Chart 7-2 may also be added. Here is a partial list of soil conditioners: FoamFoam rubber can be used in place of styrofoam. Although it holds water trapped between its open cells it also holds air. About 1.5 parts of foam rubber for every part of styrofoam is used. Pea-size pieces or smaller should be used.GravelGravel is often used as a sole medium in hydroponic systems because it is easy to clean, never wears out, does not "lock up" nutrients, and is inexpensive. It is also a good mix ingredient because it creates large spaces for airpockets and gives the mix weight. Some gravel contains limestone (see "Sand"). This material should not be used.LavaLava is a preferred medium on its own or as a part of a mix. It is porous and holds water both on its surface and in the irregular spaces along its irregular shape. Lava is an ideal medium by itself but is sometimes considered a little too dry. To give it moremoisture-holding ability, about one part of wet vermiculite ismixed with 3 to 6 parts lava. The vermiculite will break up and coat the lava, creating a mdeium with excellent water-holding abilities and plenty of air spaces. If the mix is watered from the top, the vermiculite will wash down eventually, but if it is watered from the bottom it will remain.PerlitePerlite is an expanded (puffed) volcanic glass. It is lightweight with many peaks and valleys on its surface, where it traps particles of water. However, it does not absorb water into its structure. It does not break down easily and is hard to the touch. Perlite comes in several grades with the coarser grade being better for larger containers. perlite is very dusty when dry. To eliminate dust, the material is watered to saturation with a watering can or hose before it is removed from the bag. Use of masks and respirators is important.RockwoolRockwool is made from stone which has been heated then extruded into think strands which are something like glass wool. It absorbs water like a wick. It usually comes in blocks or rolls. It can be used in all systems but is usually used in conjunction with drop emitters. Growers report phenomenal growth rates using rockwool. It is also very convenient to use. The blocks are placed in position or it is rolled out. Then seeds or transplants are placed on the material.SandSand is a heavy material which is often added to a mixture to increase its weight so that the plant is held more firmly. It promotes drainage and keeps the mix from caking. Sand comes in several grades too, but all of them seem to work well. The best sand to use is composed of quartz. Sand is often composed of limestone; the limestone/sand raised pH, causing micronutrients to precipitate, making them unavailable to the plants. It is best not to use it. Limestone-containing sand can be "cured" by soaking in a solution of water and superphosphate fertilizer which binds with the surface of the lime molecule in the sand, making the molecule temporarily inert. One pound of superphosphate is used to 5 gallons of water. It dissolves best in hot water. The sand should sit in this for 6-12 hours and then be rinsed. Superphosphate can be purchased at most nurseries. Horticultural sand is composed of inert materials and needs no curing. Sand must be made free of salt if it came from a salt-water area.Sphagnum MossSphagnum or peat moss is gathered from bogs in the midwest. It absorbs many times its own weight in water and acts as a buffer for nutrients. Buffers absorb the nutrients and hold large amounts in their chemical structure. The moss releases them gradually as they are used by the plant. If too much nutrient is supplied, the moss will act on it and hold it, preventing toxic buildups in the water solution. Moss tends to be acidic so no more than 20% of the planting mix should be composed of it.Styrofoam PelletsStyrofoam is a hydrophobic material (it repels water) and is an excellent soil mix ingredient. It allows air spaces to form in the mix and keeps the materials from clumping, since it does not bond with other materials or with itself. One problem is that it is lighter than water and tends to migrate to the top of the mix. Styrofoam is easily used to adjust the water-holding capacity of a mix. Mixes which are soggy or which hold too much water can be "dried" with the addition of styrofoam. Styrofoam balls or chips no larger than a pea should be used in fine-textured mixtures. Larger styrofoam pieces can be used in coarse mixes.VermiculiteVermiculite is porcessed puffed mica. It is very lightweight but holds large quantities of water in its structure. Vermiculite is available in several size pieces. The large size seems to permit more aeration. Vermiculite breaks down into smaller particles over a period of time. Vermiculite is sold in several grades based on the size of the particles. The fine grades are best suited to small containers. In large containers, fine particles tend to pack too tightly, not leaving enough space for air. Coarser grades should be used in larger containers. Vermiculite is dusty when dry, so it should be wet down before it is used.Mediums used in smaller containers should be able to absorb more water than mediums in larger containers. For instance, seedlings started in 1 to 2 inch containers can be planted in plain vermiculite or soil. Containers up to about one gallon can be filled with a vermiculite-perlite or soil-perlite mix. Containers larger than that need a mix modified so that it does not hold as much water and does not become soggy. The addition of sand, gravel, or styrofoam accomplishes this very easily. Here are lists of different mediums suitable for planting: Below is a list of the moist mixtures, suitable for the wick system, the reservoir system and drop emitters which are covered in part 9. Moist Planting Mixes1.4 parts topsoil, 1 part vermiculite, 1 part perlite. Moist, contains medium-high amounts of nutrients. Best for wick and hand-watering.2.3 parts topsoil, 1 part peat moss, 1 part vermiculite, 1 part perlite, 1 part styrofoam. Moist but airy. Medium nutrients. Best for wick and hand-watering. 3.3 parts vermiculite, 3 parts perlite, 1 part sand, 2 parts pea-sized gravel. Moist and airy but has some weight. Good for all systems, drains well. 4.5 parts vermiculite, 5 parts perlite. Standard mix, moist. Excellent for wick and drop emitters systems though it works well for all systems. 5.3 parts vermiculite, 1 part perlite, 1 part styrofoam. Medium dry mix, excellent for all systems. 6.2 parts vermiculite, 1 part perlite, 1 part styrofoam, 1 part peat moss. Moist mix. 7.2 parts vermiculite, 2 parts perlite, 3 parts styrofoam, 1 part sphagnum moss, 1 part compost. Medium moisture, small amounts of slow releasing nutrients, good for all systems. 8.2 parts topsoil, 2 parts compost, 1 part sand, 1 part perlite. Medium-moist, high in slow-release of organic nutrients, good for wick and drip systems, as well as hand watering. 9.2 parts compost, 1 part perlite, 1 part sand, 1 part lava. Drier mix, high in slow-release of nutrients, drains well, good for all systems. 10.1 part topsoil, 1 part compost, 2 parts sand, 1 part lava. Dry mix, high in nutrients, good for all systems. 11.3 parts compost, 3 parts sand, 2 parts perlite, 1 part peat moss, 2 parts vermiculite. Moist, mid-range nutrients, good for wick systems. 12.2 parts compost, 2 parts sand, 1 part styrofoam. Drier, high nutrients, good for all systems. 13.5 parts lava, 1 part vermiculite. Drier, airy, good for all systems.Here are some drier mediums suitable for flood systems as well as drip emitters (hydroponic systems covered in part 9). Chart 7-1-B: Flood System/Drip Emitter Mixes1.Lava 2.Pea sized gravel 3.Sand 4.Mixes of any or all of the above. Manure and other slow-releasing natural fertilizers are often added to the planting mix. With these additives, the grower needs to use ferilizers only supplementally. Some of the organic amendments are listed in the following chart. Organic amendments can be mixed but should not be used in amounts larger than those recommended because too much nutrient can cause toxicity. Some growers add time-release fertilizers to the mix. These are formulated to release nutrients over a specified period of time, usually 3, 4, 6 or 8 months. The actual rate of release is regulated in part by temperature, and since house temperatures are usually higher than outdoor soil temperatures, the fertilizers used indoors release over a shorter period of time than is noted on the label. Gardeners find that they must supplement the time-release fertilizer formulas with soluble fertilizers during the growing season. Growers can circumvent this problem by using time-release fertilizer suggested for a longer period of time than the plant cycle. For instance, a 9 month time-release fertilizer can be used in a 6 month garden. Remember that more fertilizer is releasing faster, so that a larger amount of nutrients will be available than was intended. These mixes are used sparingly. About one tablespoon of dolomite limestone should be added for each gallon of planting mix, or a half cup per cubic foot of mix. This supplies the calcium along with mangesium, both of which the plants require. If dolomite is unavailable, then hydrated lime or any agricultural lime can be used.Chart 7-2: Organic Amendments+-----------------+-----+-----+------+-------------------------------------+| Amendment | N | P | K | 1 Part : X Parts Mix | | Cow Manure | 1.5 | .85 | 1.75 | Excellent condition, breaks down | | | | | | over the growing season. 1:10 | +-----------------+-----+-----+------+-------------------------------------+ | Chicken Manure | 3 | 1.5 | .85 | Fast acting. 1:20 | +-----------------+-----+-----+------+-------------------------------------+ | Blood Meal | 15 | 1.3 | .7 | N quickly available. 1:100 | +-----------------+-----+-----+------+-------------------------------------+ | Dried Blood | 13 | 3 | 0 | Very soluble. 1:100 | +-----------------+-----+-----+------+-------------------------------------+ | Worm Castings | 3 | 1 | .5 | Releases N gradually. 1:15 | +-----------------+-----+-----+------+-------------------------------------+ | Guano | 2-8 | 2-5 | .5-3 | Varies alot, moderately soluble. | | | | | | For guano containing 2% nitrogen, | | | | | | 1:15. For 8% nitrogen, 1:40 | +-----------------+-----+-----+------+-------------------------------------+ | Cottonseed Meal | 6 | 2.5 | 1.5 | Releases N gradually. 1:30. | +-----------------+-----+-----+------+-------------------------------------+ | Greensand | 0 | 1.5 | 5 | High in micronutrients. Nutrients | | | | | | available over the season. 1:30 | +-----------------+-----+-----+------+-------------------------------------+ | Feathers | 15 | ? | ? | Breaks down slowly. 1:75 | +-----------------+-----+-----+------+-------------------------------------+ | Hair | 17 | ? | ? | Breaks down slowly. 1:75 | ------------------------------------------------------------------------ N = Nitrogen * P = Phosphorous * K = Potassium Marijuana Grower's Handbook - part 8 of 33 "Hydroponics vs. Soil Gardening" Plants growing in the wild outdoors obtain their nutrients from the breakdown of complex organic chemicals into simpler water-soluble forms. The roots catch the chemicals using a combination of electrical charges and chemical manipulation. The ecosystem is generally self-supporting. For instance, in some tropical areas most of the nutrients are actually held by living plants. As soon as the vegetation dies, bacteria and other microlife feast and render the nutrients water-soluble. They are absorbed into the soil and are almost immediately taken up by higher living plants. Farmers remove some of the nutrients from the soil when they harvest their crops. In order to replace those nutrients they add fertilizers and other soil additives. [pH : perhaps shake would be good fertilizer for one's next crop] Gardeners growing plants in containers have a closed ecology system. Once the plants use the nutrients in the medium, their growth and health is curtailed until more nutrients become available to them. It is up to the grower to supply the nutrients required by the plants. The addition of organic matter such as compost or manure to the medium allows the plant to obtain nutrients for a while without the use of water-soluble fertilizers. However, once these nutrients are used up, growers usually add water-soluble nutrients when they water. Without realizing it, they are gardening hydroponically. Hydroponics is the art of growing plants, usually without soil, using water-soluble fertilizers as the main or sole source of nutrients. The plants are grown in a non-nutritive medium such as gravel or sand or in lightweight materials such as perlite, vermiculite or styrofoam. The advantages of a hydroponic system over conventional horticultural methods are numerous: dry dpots, root drowning and soggy conditions do not occur. Nutrient and pH problems are largely eliminated since the grower maintains tight control over their concentration; there is little chance of "lockup" which occurs when the nutrients are fixed in the soil and unavailable to the plant; plants can be grown more conveniently in small containers; and owing to the fact that there is no messing around with soil, the whole operation is easier, cleaner, and much less bothersome than when using conventional growing techniques. "Hydroponic Systems"Most hydroponic systems fall into one of two broad categories: passive or active. Passive systems such as reservoir or wick setups depend on the molecular action inherent in the wick or medium to make water available to the plant. Active systems which include the flood, recirculating drop and aerated water systems, use a pump to send nourishment to the plants. Most commercially made "hobby" hydroponic systems designed for general use are shallow and wide, so that an intensive garden with a variety of plants can be grown. But most marijuana growers prefer to grow each plant in an individual container.PASSIVE HYDROPONIC SYSTEMSThe Wick SystemThe wick system is inexpensive, easy to set up and easy to maintain. The principle behind this type of passive system is that a length of 3/8 to 5/8 inch thick braided nylon rope, used as a wick, will draw water up to the medium and keep it moist. The container, which can be an ordinary nursery pot, holds a rooting medium and has wicks runing along the bottom, drooping through the holes at the bottom, reaching down into a reservoir. Keeping the holes in the container small makes it difficult for roots to pentrate to the reservoir. The amount of water delivered to the medium can be increased by increasing the number, length, or diameter of the wicks in contact with the medium.A 1 gallon container needs only a single wick, a three gallon container should have two wicks, a five gallon container, three wicks. The wick system is self regulating; the amount of water delivered depnds on the amount lost through evaporation or transpiration. Each medium has a maximum saturation level. Beyond that point, an increase in the number of wicks will not increase the moisture level. A 1-1-1 combination of vermiculite, perlite, and styrofoam is a convenient medium because the components are lightweight and readily available. Some commercial units are supplied with coarse vermiculite. To increase weight so that the plant will not tip the container over when it gets large, some of the perlite in the recipe can be replaced with sand. The bottom inch or two of the container should be filled only with vermiculite, which is very absorbent, so that the wicks have a good medium for moisture transfer. Wick systems are easy to construct. The wick should extend 5 inches or more down from the container. Two bricks, blocks of wood, or styrofoam are placed on the bottom of a deep tray (a plastic tray or oil drip pan will do fine.) Then the container is placed on the blocks so that the wicks are touching the bottom of the tray. The tray is filled with a nutrient/water solution. Water is replaced in the tray as it evaporates or is absorbed by the medium through the wick. A variation of this system can be constructed using an additional outer container rather than a tray. With this method less water is lost due to evaporation. To make sure that the containers git together and come apart easily, bricks or wood blocks are placed in the bottom of the outer container. The container is filled with the nutrient/water solution until the water comes to just below the bottom of the inner container. Automating this system is simple to do. Each of the tray or bottom containers is connected by tubing to a bucket containing a float valve such as found in toilets. The valve is adjusted so that it shuts off when the water reaches a height about 1/2 inch below the bottom of the growing containers. The bucket with the float valve is connected to a large reservoir such as a plastic garbage can or 55 gallon drum. Holes can be drilled in the containers to accomodate the tubing required, or the tubes can be inserted from the top of the containers or trays. The tubes should be secured or weighted down so that they do not slip out and cause floods. The automated wick system works as a siphon. To get it started, the valve container is primed and raised above the level of the individual trays. Water flows from the valve to the plant trays as a result of gravity. Once the containers have filled and displaced air from the tubes, the water is automatically siphoned and the valve container can be lowers. Each container receives water as it needs it. A simpler system can be devised by using a plastic kiddie pool and some 4x4's or a woodem pallet. Wood is placed in the pool so that the pots sit firmly on the board; the pool is then filled with water up to the bottom of the pots. The wicks move the water to the pots. Wick systems and automated wick systems are available from several manufacturers. Because they require no moving parts, they are generally reliable although much more expensive than homemande ones, which are very simple to make. Wick system units can be filled with any of the mixes found in Chart 7-1-A. The Reservoir SystemThe reservoir system is even less complex than the wick system. For this setup all a grower needs to do is fill the bottom 2 or 3 inches of a 12 inch deep container with a coarse, porous, inert medium such as lava, ceramic beads or chopped unglazed pottery. The remaining portion is filled with one of the mixes containing styrofoam. The container is placed in a tray, and sits directly in a nutrient-water solution 2-3 inches deep. The system is automated by placing the containers in a trough or large tray. Kiddie pools can also be used. The water is not replaced until the holding tray dies. Passive systems should be watered from the top down once a month so that any buildup of nutrient salts caused by evaporation gets washed back to the bottom.ACTIVE HYDROPONIC SYSTEMSActive systems move the water using mechanical devices in order to deliver it to the plants. There are many variations on active systems but most of them fall into one of three categories: flood systems, drip systems, or nutrient film systems.The Flood SystemThe flood system is the type of unit that most people think of when hydroponics is mentioned. The system usually has a reservoir which periodically empties to flood the container or tub holding the medium. The medium holds enough moisture between irrigations to meet the needs of the plant. Older commercial greenhouses using this method often held long troughs or beds of gravel. Today, flood systems are designed using individual containers. Each container is attached to the reservoir using tubing. A simple flood system can be constructed using a container with a tube attached at the bottom of a plastic container [pH: that which the plant is placed in] and a jug. The tube should reach down to the jug, which should be placed below the bottom of the growing container. To water, the tube is held above the container so that it doesn't drop. The water is poured from the jug into the container. Next, the tube is placed in the jug and put back into position, below the growing container. The water will drain back into the jug. Of course, not as much will drain back in as was poured out. Some of the water was retained in the growing unit. Automating this unit is not difficult. A two-holed stopper is placed in the jug. A tube from the growing unit should reach the bottom of the reservoir container. Another tube should be attached to the other stopper hole and then to a small aquarium-type air pump which is regulated by a timer. When the pump turns on, it pushes air into the jug, forcing the water into the container. When the pump goes off, the water is forced back into the jug by gravity. Several growing units can be hooked up to a large central reservoir and pump to make a large system. The water loss can automatically be replaced using a float valve, similar to the ones used to regulate water in a toilet. Some growers place a second tube near the top of the container which they use as an overflow drain. Another system uses a reservoir above the growing container level. A water timing valve or solenoid valve keeps the water in the reservoir most of the time. When the valve opens, the water fills the growing containers as well as a central chamber which are both at the same height. The growing chambers and the central chamber are attached to each other. The water level is regulated by a float valve and a sump pump. When the water level reaches a certain height, near the top of the pots, the sump pump automatically turns on and the water is pumped back up to the reservoir. One grower used a kiddie pool, timer valve, flower pots, a raised reservoir and a sump pump. He placed the containers in the kiddie pool along with the sump pump and a float valve. When the timer valve opened, the water rushed from the tank to the kiddie pool, flooding the containers. The pump turned on when the water was two inches from the top of the containers and emptied the pool. Only when the valve reopened did the plants receive more water. With this system, growers have a choice of mediums, including sand, gravel, lava, foam or chopped-up rubber. Vermiculite, perlite, and styrofoam are too light to use. The styrofoam and perlite float, and the vermiculite becomes too soggy. The plants' water needs to increase during the lighted part of the daily cycle, so the best time to water is as the light cycle begins. If the medium does not hold enough moisture between waterings, the frequency of waterings is increased. There are a number of companies which manufacture flood systems. Most of the commercially made ones work well, but they tend to be on the expensive side. They are convenient, though.The Drip SystemYears ago, the most sophisticated commercial greenhouses used drip emitter systems which were considered exotic and sophisticated engineering feats. These days, gardeners can go to any well-equipped nursery and find all of the materials necessary to design and build the most sophisticated drop systems. These units consist of tubing and emitters which regulate the amount of water delivered to each individual container. Several types of systems can be designed using these devices. The easiest system to make is a non-return drain unit. The plants are watered periodically using a diluted nutrient solution. Excess water drains from the containers and out of the system. This system is only practical when there is a drain in the growing area. If each container has a growing tray to catch excess water and the water control valve is adjusted closely, any excess water can be held in the tray and eventually used by the plant or evaporated. Once a gardener gets the hang of it, matching the amount of water delivered to the amount needed is easy to do. One grower developed a drip emitter system which re-uses water by building a wooden frame using 2x4's and covering it with corrugated plastic sheeting. She designed it so that there was a slight slope. The containers were placed on the corrugated plastic, so the water drained along the corrugations into a rain drainage trough, which drained into a 2 or 3 gallon holding tank. The water was pumped from the holding taink back to the reservoir. The water was released from the reservoir using a timer valve.Aerated WaterThe aerated water system is probably the most complex of the hydroponic systems because it allows for the least margin of error. It should only be used by growers with previous hydroponic experience. The idea of the system is that the plant can grow in water as long as the roots receive adequate amounts of oxygen. To provide the oxygen, an air pump is used to oxygenate the water through bubbling and also by increasing the circulation of the water so that there is more contact with air. The plants can be grown in individual containers, each with its own bubbler or in a single flooded unit in which containers are placed. One grower used a vinyl covered tank he constructed. He placed individual containers that he made into the tank. His containers were made of heavy-duty nylon mesh used by beermakers for soaking hops. This did not prevent water from circulating around the roots. Aerated water systems are easy to build. A small aquarium air pump supplies all the water that is required. An aerator should be connected to the end and a clear channel made in the container for the air. The air channel allows the air to circulate and not disturb the roots. Gravel, lava, or ceramic is used.Nutrient Film TechniqueThe nutrient film technique is so named because the system creates a film of water that is constantly moving around the roots. This technique is used in many commercial greenhouses to cultivate fast growing vegetables such as lettuce without any medium. The plants are supported by collars which hold them in place. This method is unfeasible for marijuana growers. However, it can be modified a bit to create an easy-to-care-for garden. Nursery suppliers sell water mats, which disperse water from a soaker hose to a nylon mat. The plants grow in the bottomless containers which sit on the mat. The medium absorbs water directly from the mat. In order to hold the medium in place, it is placed in a nylon net bag in the container."Growing in the Ground"Some growers have the opportunity to grow plants directly in the ground. Many greenhouses are built directly over the earth. Growing directly in the soil has many advantages over container growing. A considerable amount of labor may be eliminated because there is no need to prepare labor-intensive containers with expensive medium. Another advantage is that the plants' needs are met more easily. Before using any greenhouse soil, it is necessary to test it. The pH and fertility of soils vary so much that there are few generalizations that can be made about them. The most important quality of any soil is its texture. Soils which drain well usually are composed of particles of varying size. This creates paths for water to flow and also allows airs pockets to remain even when the soil is saturated. Soils composed of very fine particles, such as mucks and clay, do not drain well. Few air particles are trapped in these soils when they are saturated. When this happens, the roots are unable to obtain oxygen and they weaken when they are attacked by anaerobic bacteria. These soils should be adjusted with sand and organic matter which help give the medium some porosity. Materials suitable for this include sand, compost, composted manure, as well as perlite, lava, gravel, sphagnum moss, styrofoam particles and foam particles. Low lying areas may have a very high water table so that the soils remain saturated most of the time. One way to deal with this problem is to create a series of mounds or raised beds so that the roots are in ground at higher level than the floor level. Once soil nutrient values are determined, adjustments can be made in the soil's fertility. For marijuana, the soil should test high in total Nitrogen, and the medium should test high in Phosphorous and Potassium. This is covered in subsequent files. Growers use several methods to prepare the soil. Some prefer to till the whole area using either a fork, a roto-tiller or a small tractor and plow. The marijuana plant grows both vertical and horizontal roots. The horizontal roots grow from the surface to a depth of 9-18 inches depending on the soil's moisture. They grow closer to the surface of moist soils. The vertical root can stretch down several feet in search of water. In moist soils, the vertical roots may be short, even stunted. Soil with loose texture, sandy soils, and soils high in organic matter may have adequate aeration, porosity, and space for roots and may not have to be tilled at all. Most soils should be dug to a depth of 6-9 inches. The tighter the soil's texture, the deeper it should be filled. If the soil is compacted, it is dug to a depth of two feet. This can be done by plowing and moving the soil in alternate rows and then plowing the newly uncovered soil. Soil texture adjustors such as gypsum are added to the bottom layer of the soil as well as the top layer, but soil amendments such as fertilizers or compst are added only to the top layer, where most of the plant's roots are. Then the soil is moved back into the troughs and the alternate rows are prepared the same way. A variation of this technique is the raised bed. First, the whole area is turned, and then aisles are constructed by digging out the pathways and adding the material to the beds. With the addition of organic soil amendments, the total depth of prepared soil may stretch down 18 inches. Some growers use planting holes rather than tilling the soil. A hole ranging between 1 and 3 feet wide and 1.5 and 3 feet deep is dug at each space where there is to be a plant. The digging can be facilitated using a post hole digger, electric shovel, or even a small backhoe or power hole digger. Once the hole is dug the soil is adjusted with amendments or even replaced with a mix. No matter how the soil is prepared, the groundwater level and the permeability of the lower layers is of utmost importance. Areas with high water tables, or underlying clay or hardpan will not drain well. In either case the harden should be grown in raised beds which allow drainage through the aisles and out of the growing area, rather than relying on downward movement through soil layers. Soils in used greenhouses may be quite imbalanced even if the plants were growing in containers. The soil may have a buildup of mutrient salts, either from runoff or direct application, and pesticides and herbicides may be present. In soils with high water tables, the nutrients and chemicals have nowhere to go, so they dissolve and spread out horizontally as well as vertically, contaminating the soil in surrounding areas. Excess salts can be flushed from the soil by flooding the area with water and letting it drain to the water table. In areas with high water tables, flushing is much more difficult. Trenches are dug around the perimeter of the garden which is then flooded with nutrient-free water. As the water drains into the trenches, it is removed with a pump and transported to another location. Pesticides and herbicides may be much mroe difficult to remove. Soils contaminated with significant amounts of residues may be unsuitable for use with material to be ingested or inhaled. Instead, the garden should be grown in containers using nonindigenous materials. Usually plants are sexed before they are planted into the ground. If the soil showed adequate nutrient values no fertilizer or side dressing will be required for several months. Several growers have used ingenious techniqures to provide their gardens with earthy environments. One grower in Oregon chopped through the concrete floor of his garage to make planting holes. The concrete had been poured over sub-soil so he dug out the holes and replaced the sub-soil with a mixture of composted manure, vermiculite, perlite, worm castings, and other organic ingredients. He has been using the holes for several years. After several crops, he redigs the holes and adds new ingredients to the mix. A grower in Philadelphia lived in a house with a backyard which was cemented over. He constructed a raised bed over the concrete using railroad ties and filled it with a rich topsoil and composted manure mixture, then built his greenhouse over that. The growing bed is about 15 inches deep and the grower reports incredible growth rates."Lighting and Lights"Green plants use light for several purposes. The most amazing thing that they can do with it is to use the energy contained in light to make sugar from water and carbon dioxide. This process is called photosynthesis and it provides the basic building block for most life on Earth. Plants convert the sugars they make into starches and then into complex molecules composed of starches, such as cellulose. Amino acids, the building blocks of all proteins, are formed with the addition of nitrogen atoms. Plants also use ligh to regulate their other life processes. As we mentioned earlier, marijuana regulates its flowering based on the number of hours of uniterrupted darkness. (See part 25, Flowering) Sunlight is seen as white light, but is composed of a broadf band of colors which cover the optic spectrum. Plants use red and blue light most efficiently for photosynthesis and to regulate other processes. However, they do use other light colors as well for photosynthesis. In fact, they use every color except green, which they reflect back. (That is why plants appear green; they absorb all the other spectrums except green.) In controlled experiements, plants respond more to the toal amount of light received than to the spectrums in which it was delivered. The best source of light is the sun. It requires no expense, no electricity, and does not draw suspicion. It is brighter than artifical light and is self regulating. Gardeners can use the sun as a primary source of light if they have a large window, skylight, translucent roof, enclosed patio, roof garden, or greenhouse. These gardens may require some supplemental lightning, especially if the light enters from a small area such as a skylight, in order to fill a large area. It is hard to say just how much supplemental light a garden needs. Bright spaces which are lit from unobstructed overhead light such as a greenhouse or a large southern window need no light during the summer but may need artificial light during the winter to supplement the weak sunlight or overcast conditions. Spaces receiving indirect sunlight during the summer may need some supplemental lighting. Light requirements vary by variety. During the growth cycle, most varieties will do well with 1000-1500 lumens per square foot although the plants can usemore lumens, up to 3000, efficiently. Equatorial varieties may develop long internodes (spaces on the stem between the leaves) when grown under less that bright conditions. During flowering, indica varieties can mature well on 2000 lumens. Equatorial varieties require 2500-5000 lumens. Indica-sativa F1 (first generation) hybrids usually do well on 2500-3000 lumens. Some light meters have a foot-candle readout. Thirty-five millimeter cameras that have built-in light meters can also be used. In either case, a sheet of white paper is placed at the point to be measured so it reflects the light most brilliantly. Then the meter is focused entirely on the paper. The camera is set for ASA 100 film and the shutter is set for 1/60 second. A 50 mm or "normal" lens is used. Using the manual mode, the camera is adjusted to the correct f-stop. The conversion chart, 10-1, shows the amount of light hitting the paper. Most growers, for one reason or another, are not able to use natural light to grow marijuana. Instead, they use artificial lights to provide the light energy which plants require to photosynthesize, regulate their metabolism, and ultimately to grow. There are a number of sources of artificial lighting. Cultivators rarely use incandescent or quartz halogen lights. They convert only about 10% of the energy they use to light and are considered inefficient.Chart 10-1: Footcandles
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On some cameras it is easier to adjust the shutter speed, keeping the f.stop set at f.4 (at ASA 100): +----------------+-------------+
FLUORESCENT TUBESGrowers have used flurorescent tubes to provide light for many years. They are inexpensive, are easy to set up, and are very effective. Plants grow and bud well under them. They are two to three times as efficient as incandescents. Until recently, fluorescents came mostly in straight lengths of 2, 4, 6, or 8 feet, which were placed in standard reflectors. Now there are many more options for the fluorescent user. One of the most convenient fixtures to use is the screw-in converter for use in incandescent sockets, which come with 8 or 12 inch diameter circular fluorescent tubes. A U-shaped 9 inch screw-in fluorecent is also available. Another convenient fixture is the "light wand", which is a 4 foot, very portable tube. It is not saddled with a cumbersome reflector. Fluorescents come in various spectrums as determined by the type of phosphor with which the surface of the tube is coated. Each phosphor emits a different set of colors. Each tube has a spectrum identification such as "warm white", "cool white", "daylight", or "deluxe cool white" to name a few. This signifies the kind of light the tube produces. For best results, growers use a mixture of tubes which have various shades of white light. Once company manufactures a fluorescent tube which is supposed to reproduce the sun's spectrum. It is called the Vita-Lite and works well. it comes in a more efficient version, the "Power Twist", which uses the same amount of electricity but emits more light because it has a larger surface area. "Gro-Tubes" do not work as well as regular fluorescents even though they produce light mainly in the red and blue spectrums. They produce a lot less light than the other tubes. To maintain a fast growing garden, a minimum of 20 watts of fluorescent light per square foot is required. As long as the plants' other needs are met, the more light that the plants receive, the faster and bushier they will grow. The plants' buds will also be heavier and more developed. Standard straight-tubed fluorescent lamps use 8-10 watts per linear foot. To light a garden, 2 tubes are required for each foot of width. The 8 inch diameter circular tubes use 22 watts, the 12 inch diameter use 32 watts. Using straight tubes, it is possible to fit no more than 4 tubes in each foot of width because of the size of the tubes. A unit using a combination of 8 and 12 inch circular tubes has an input of 54 watts per square foot. Some companies manufacture energy-saving electronic ballasts designed for use with special fluorescent tubes. These units use 39% less electricity and emit 91% of the light of standard tubes. For instance, an Optimizer warm light white 4 foot tube uses 28 watts and emits 2475 lumens. Both standard and VHO ballasts manufactured before 1980 are not recommended. They were insulated using carcinogenic PCB's and they are a danger to your health should they leak. The shape of the fluorescent reflector used determines, to a great extent, how much light the plants receive. Fluorescent tubes emit light from their entire surface so that some of the light is directed at the reflector surfaces. Many fixtures place the tubes very close to each other so that only about 40% of the light is actually transmitted out of the unit. The rest of it is trapped between the tubes or between the tubes and the reflector. This light may as well not be emitted since it is doing no good. A better reflector can be constructed using a wooden frame. Place the tube holders at equal distances from each other at least 4 inches |