Cannabis (drug) cultivation

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Cannabis cultivation is the cultivation of the Cannabis sativa plant. Subspecies are C. sativa subsp. sativa and C. sativa subsp. indica. Wild or escaped Cannabis, previously classified as Cannabis ruderalis, is now regarded as the variety C. sativa subsp sativa var. spontanea. Various hybrids are cultivated. Cannabis is grown for a variety of purposes, including as a source of materials for use in various products, such as food, clothing, cosmetics and fuel and for the production of cannabis drug materials. Cultivation techniques for other purposes are very different: see Hemp.

The drug material is used medicinally, recreationally, and spiritually, but its possession is illegal in most places. See: Legal issues of cannabis.

The legal status of cannabis has led growers to implement novel cultivation methods for indoor growing, in order to avoid aerial surveillance of outdoor plots. These methods include: using a water or air-based growth medium (known as hydroponics and aeroponics respectively); the use of homemade organic composted fertilizers; training and trellising techniques such as Screen of Green (also known as SCROG), Sea of Green (also known as SOG); and entire systems and methods such as the NIMBY no-dump method, or the Krusty Freedom Bucket method. Research into the production of cannabis for the drug Marinol and other more profitable and marketable forms of cannabis based medicines has further pushed the envelope of cannabis cultivation in all forms of laboratory, both public and private.

The emphasis on advanced cultivation techniques, as well as the availability of hybrid strains (with names like Northern Lights, Blueberry, NYC Diesel), is believed to be a factor in the increase in the overall quality and variety of commercially-available cannabis over the past few decades. However, it should be noted that well-grown heirloom strains (e.g. Thai, Colombian Gold, Panama Red) are still in use. The following covers the plant's entire growth, from germination to harvest.

Contents 1 Botany 2 Traditional indoor cultivation 2.1 Lighting 2.2 Atmosphere 2.3 Germination 2.4 Vegetative phase of growth 2.5 Reproductive/flowering phase of growth 3 Traditional outdoor cultivation techniques 3.1 Harvest and processing 3.2 Drying 3.3 Curing 3.4 Hash 4 Alternative cultivation techniques 4.1 Hydroponic cultivation 4.2 Organic cultivation 4.3 Screen of green 4.4 Sea of green 4.5 Sinsemilla 5 Genetics and breeding 5.1 Selection of mother plants 5.2 Feminized seeds 5.3 Hybrid vigor 5.4 Cloning from cuttings 6 Detection and the law 6.1 Outdoors 6.2 Indoors 7 See also 8 References 9 External links

[edit] Botany

Main article: Cannabis

Cannabis is a genus in the family Cannabaceae, like hops. Cannabis is an annual plant and usually dioecious, which means it has separate pistillate (female) and stamenate (male) plants. A shorter photoperiod (day length) towards the end of the growing season is generally required to induce the reproductive (sometimes called flowering or budding) phase of growth, however some cultivars of Cannabis are auto-flowering, which means that they will flower regardless of the photoperiod.

The leaves are palmately compound, with serrate leaflets. During vegetative phase of growth, there is one leaflet on the first true leaf, three leaflets on the second, five on the third, and so on, up to about seven for C. sativa subsp. indica, and eleven for C. sativa subsp. sativa. The phyllotaxy reverses during reproductive phase, with bud leaves initially containing seven to eleven leaflets, and progressing down to one leaflet, and ultimately none at the terminal bud. Leaf arrangement is opposite during vegetative phase, and alternate during reproductive phase.

Cannabis plants are known for their production of oils, fibers, and compounds known as cannabinoids, including psychoactive tetrahydrocannabinol (THC) and non-psychoactive cannabidiol (CBD). Cannabis plants can be categorized on the basis of drug potential by the overall amount of cannabinoids produced, as well as by the relative ratio of THC to CBD. Overall cannabinoid production is influenced by environmental factors, but THC/CBD ratios are genetically determined and remain fixed throughout the life of the plant. This system of categorization recognizes three distinct categories. Non-drug (or low-intoxicant) types produce low levels of THC and CBD in both male and female plants. Drug types produce high amounts of THC but relatively low levels of CBD in both male and female plants. Intermediate types produce moderate amounts of THC, and produce CBD in comparable amounts; male plants of this intermediate type do not produce sufficient amounts of THC to be useful for drug purposes, while female plants may produce enough THC to be useful for drug production. ^[1][2]

The genus Cannabis comprises a single species: Cannabis sativa. Two subspecies are recognized: C. sativa subsp. sativa and C. sativa subsp. indica ^[3](but this classification is not universally accepted ^[1]). Wild or escaped Cannabis was previously classified as a distinct species Cannabis ruderalis, but is now regarded as a variety, C. sativa subsp. sativa var. spontanea.^[3]

Generally only non-drug cultivars of C. sativa subsp. sativa are grown for industrial/agricultural purposes. For recreational or medicinal purposes, high-cannabinoid cultivars of both C. sativa subsp. sativa and C. sativa subsp. indica are grown,^[4] as well as hybrids of the two subspecies, and even a few hybrids that allegedly contain some C. sativa subsp. sativa var spontanea genetics.

Cultivation of the plant typically focuses on production of one of its above-noted ingredients. It is possible to grow the plants in a very close matrix, whereupon the resultant plants will have very fine fibers, which can be used to make fine cloth resembling silk. Alternatively, plants with select genetics, which are grown under close nutrient supervision and adequate lighting will produce higher quantities of THC.

While it is possible to grow cannabis simply for the purpose of a houseplant or as a hobby, the practice is quite challenging due to the need to keep the annual plant in a near perpetual vegetative state, which requires root pruning and artificial lighting for the winter months.

[edit] Traditional indoor cultivation

This section covers the traditional method of cultivating medicinal or recreational marijuana indoors, growing the plants in a soil-like medium and adding fertilizer when the plants are given water. Traditional outdoor cultivation techniques are covered in the next section, and alternative techniques, such as hydroponics and organic cultivation techniques, are discussed in the last section.

Cultivating marijuana indoors is more complicated and expensive than growing outdoors, but it allows the cultivator complete control over the growing environment. Cannabis grown outdoors can be just as potent as its indoor counterpart if tended to properly.

[edit] Lighting

The single most important factor for the indoor cultivator to consider is lighting. Since cultivation of cannabis is harshly punished in some areas, many cultivators must set up a hidden indoor grow room and provide artificial light. Additionally, outdoor cultivators usually start their clones or seedlings indoors, under artificial light. Lighting types include fluorescent, high-intensity discharge (HID) including metal halide(MH), high pressure sodium (HPS), and LED^{[citation needed]}. Fluorescent lights have the advantage of coolness, and are gentle enough to use on seedlings and rooting clones. HID lamps are the most efficient, and are usually used between 250-1000 watts.^{[citation needed]}

While cannabis will grow under most light spectra,all plants prefer a full spectrum light. A test done by Ed Rosenthal^{[citation needed]} found that when a room was set up using both HPS and MH lamps the plants in between the two lights did better than those under MH alone but not as well as those under HPS. However, Cannabis can be grown successfully under both types of light. Metal halide is used for vegetative phase of growth, as it encourages short internodes (distance between sets of leaves), and inhibits cell elongation, creating a shorter, stockier plant. Unlike high pressure sodium lamps, metal halide lamps also produce ultraviolet radiation, which may play a role in increasing the amount of THC produced by the plant. High pressure sodium lamps are the choice of most growers who have only one lamp ^{[citation needed]}. HPS lamps are an used for the reproductive phase of growth, as they trigger a greater flowering response in the plant.

If high pressure sodium is used for vegetative phase, plants will usually grow slightly more quickly, but will also have longer internodes, and may be taller.^{[citation needed]}

Recent advancements in LEDs have allowed for the production of relatively cheap, bright and long lasting grow lights that emit only the colors of light required for plant growth. These lights are attractive to indoor-growers since they do not consume as much power, do not require ballasts, and produce a fraction of the heat of HID lamps.The lamps consist of arrays of many wide-spectrum red and a few narrow-spectrum blue LEDs of specific wavelengths. Although LED grow lights have shown promise through plant research by NASA and many universities, it is unknown whether the results are applicable to Cannabis cultivation. ^{[citation needed]}

According to the inverse square law, the intensity of light radiating from a point source (in this case a bulb) is inversely proportional to the square of the distance from the source. So if an object is twice as far away, it receives only 1/4 the light. This is a serious hurdle for indoor marijuana growers, and many techniques are employed to use light as efficiently as possible.

Reflectors are often used to maximize light efficiency. Plants or lights are moved so that they receive equal lighting. Some marijuana cultivators cover the walls of their grow-room with some type of reflective material.

The most commonly used covering is 6 mil (150 µm) PVC plastic sheeting that is white on one side and black on the other. The plastic is installed with the white side facing in to the room to reflect light, and the black facing the wall, to reduce fungus and mold growth. Another common covering is flat white paint, with a high titanium dioxide content to maximize reflectivity. Mylar sheeting is also sometimes used, along with Astrofoil(which also reflects heat), and Foylon(a foil-laminated, reinforced fabric).

[edit] Atmosphere

When growing indoors, the cultivator must maintain an ideal atmosphere inside the grow-room. The air temperature must be maintained within an ideal range, with a cooler night and warmer day, and adequate levels of CO₂ must be maintained in order for the plants to grow most efficiently. It is also important to promote vigorous air circulation within the grow room, which is usually accomplished by mounting one or more oscillating fans in the room, depending on its size. Using an air extraction fan, sometimes with a smaller fan, ensures air exchange.

Assuming that adequate light levels are present in the grow room, the limiting factor in plant growth is the level of carbon dioxide (CO₂). Plants grown with supplemental carbon dioxide will grow more quickly, have larger stomata, and can utilize more light. Ways of increasing carbon dioxide levels in the grow-room include: bottled carbon dioxide, carbon dioxide generators, a milk jug and yeast solution, in which yeast grows in a container, emitting CO₂, a baking soda and vinegar mixture in a container, or dry ice.^[5]

Most strains of marijuana emit a distinctive odor during their reproductive phase. This presents difficulties to those who are cultivating in places where it is illegal. The most common way of eliminating odor is by forcing odorous air through a carbon filter. Many cultivators simply attach a large carbon filter to their air extraction system, thereby filtering any smell before the air is expelled from the grow-room. Another way of eliminating odor is by installing an ozone generator in the extraction ducting. The air is forced past the ozone generator by the extraction fan, and the odorous air is neutralized as it mixes with the ozone. Cultivators must be sure that the air is thoroughly mixed before it is expelled outside, lest some odor escape. Ozone itself has a distinctive smell.

[edit] Germination

Seeds may be germinated by soaking in paper towels, or a cup of water at room temperature, or in wet Jiffy pellets. Jiffy pellets are often used because they make unnecessary the transplanting of fragile seedlings, as the saturated pellets with their seedlings can be planted directly in the intended growing medium with a minimum of trouble and effort.

[edit] Vegetative phase of growth

When true leaves have formed, the plant begins the vegetative phase of growth. During the vegetative phase of growth, the plant directs its energy resources primarily to the growth of leaves, stems, and roots. A strong root system is imperative, as it is required for strong floral development. A plant needs 1 or 2 months to mature before blooming. The plant is ready when it has revealed its sex. The males are then culled when they are identified, because they don't produce buds or flowers. If males are allowed to pollinate the females their potency will be greatly reduced.

During the vegetative phase of growth, cultivators generally employ an 18 to 24 hour photoperiod, as the plants grow more quickly if they receive more light, although a warmer and cooler period are required for optimal health. While no dark period is required, there is debate among cultivators as to whether a dark period is beneficial, and many continue to employ a dark period.

Marijuana cultivators employ fertilizers high in nitrogen and potassium during this stage, as well as a complete micronutrient fertilizer. The strength of the fertilizer is gradually increased as the plants grow and become more hardy.

The modification of a plant's growth habit is called training. Indoor cultivators employ many training techniques in order to encourage shorter plants and more dense canopy growth. For example, unless the crop is too large to be extensively pruned, cultivators will remove adventitious growth shoots, often called suckers, that are near the bottom of the plant and/or receive little light and will produce poor quality buds.

Many cultivators also employ other techniques:

Topping is done by removing the top of the apical meristem (dominant central stem), called the apex or terminal bud, in order to transfer apical dominance (the tendency for the apex to grow more rapidly than the rest of the plant) to the shoots emanating from the two nodes immediately beneath the pruning cut. This process can be repeated on one or both of the two new meristems, when they become apically dominant, with the same results. This process can actually be repeated almost infinitely, but over-diffusion of apical dominance will produce smaller, lower quality buds, so it is usually done no more than a few times. Topping also causes more rapid growth of all of the branches below the cut while the plant heals.

Pinching is similar to topping in that it causes the lower branches to grow more rapidly, but the apical meristem will maintain apical dominance, which is especially useful if the plant has already been topped. Pinching is performed by firmly pinching the apical meristem(s) so as to substantially damage vascular and structural cells but without totally breaking the stem. This will cause the lower limbs to grow more rapidly while the pinched tissue heals, after which time the stem will resume apical dominance.

[edit] Reproductive/flowering phase of growth

The plant will be induced to flowering by decreasing light from 18-24 hours a day to dark cycles of 11-12 hours that simulate the oncoming winter in the fall as the days grow shorter. Flowering generally lasts from 50 to 90 days indoors, if growing outdoors it may take somewhat longer, depending on the natural onset of the colder seasons. Once a plant is big enough to mature, dark periods are required for most plants to flower and bear fruit.

Outdoors, in spring and autumn, the nights are sufficiently long to induce flowering at all times. If possible, merely bringing the plants from indoors to the outside at these times will permit natural flowering.

[edit] Traditional outdoor cultivation techniques

When cultivated outdoors, the chosen areas are those which receive twelve hours or more of sunlight in a given day. Northern locations are preferred (Humboldt County, California and British Columbia being particularly notable), but southern locations (such as Maui, Hawaii) are also known to be good producers.

In instances where the local laws do not permit growing cannabis, cultivators may choose to grow in forests or rugged and rural areas where the local population are not likely to find the crop. Another technique is to grow cannabis in a crop that is larger and obscures the plants, such as maize. This is reported by the United States government to be common in the midwestern states. Bamboo and elderberry are also used as camouflage companion plants.

Some government organizations have claimed that in state and national parks, people have been injured by these "rebel farmers" protecting their crops, including a well documented developing problem with Mexican cartels growing cannabis in US national parks and forests.

[edit] Harvest and processing

Buds are typically harvested when fully ripe. Generally, ripeness is defined as when the white pistils start to turn dark yellow, orange, light to mid red, etc. and the trichomes, "crystals", barely begin to turn milky from clear. These trichomes can range from completely clear (generally deemed underdeveloped), to amberish-red. Ideally, professionals will use a decent power magnifying glass, a brix meter (to measure "sugar" content), and a microscope. The potential seed pods swell with resins usually reserved for seed production, thus improving the quality of the buds (called colitas), which will swell to form full "colas". If harvested early on with only a few of the pistils turned color, the buds will have a more pure THC content and less of the cannabinoids CBD and CBN. The later psychoactive substances will create the bouquet of the marijuana, and influence the overall nature of the high from anywhere from purely psychedelic to purely sedative.

Contrary to sinsemilla (bud production focused cultivation), seeds are harvested when fully developed and often after the accompanying buds have begun to deteriorate. In contrast, hemp grown for fibre is harvested before flowering, and cannabis grown for cloning is not flowered at all.

[edit] Drying

The plants are dried slowly over 1-2 weeks at roughly room temperature. A stable temperature preserves cannabinoids well. Flowers are hung by their stalks, allowing the internal fluids of the plant to remain in the flowers. Roots are removed. When the stems in the middle of the largest buds can be snapped easily, the plant is dry enough to be cured. Drying is done in a dark place, as trichomes will deteriorate if exposed to light.

[edit] Curing

The curing process continues breaking down sugars and helps develop taste and smoothness of smoke. Usually, the dried product is packed (not compressed) into glass canning jars which are airtight. Initially the product is checked periodically (every few hours) to make sure it was properly dried and has not remoistened itself. After several days, when the product is dried to satisfaction, the jars are sealed off and opened just once a week. Curing is highly varied—the minimum is usually two weeks. Some growers even cure as long as six months, while others do not cure at all. As with tobacco, curing can make the cannabis more pleasant to smoke. For the same reasons as when drying, curing jars are stored in a cool, dark, place.

A recent method of curing is called water curing. This method is quicker and can improve a lower quality product. The buds are submersed in water for a period of 7 straight days, changing the water daily. The buds are then dried and are ready to use. When water curing, nutrients can be added to the plants up until they are harvested. The water will flush out harmful chemicals (such as the ones used to feed the plants) as well as proteins, sugars, pigments and some resins. This will also increase the THC to weight ratio. ^[6]

[edit] Hash

Main article: Hashish

Hashish can be produced by several methods. The method most employed in the West is to take the plants or flowers and beat them against a screen. This causes the trichomes to break off the plants, and be collected under the screen, which serves as a crude filter. In the East, in larger fields, workers wearing leather coats run among the dense plants, and then like bees gather the pollen and trichromes off of their limbs, pressing it into shapes. ^{[citation needed]}

Bubble hash. One of the most preferred forms of hashish production is via the use of a bubble hash bag kit, such kits are typically expensive but like everything else in cannabis cultivation, it can be an investment that pays for itself. After a harvest, there are typically many green leaves- particularly large shade leaves- which themselves cannot be smoked, but have collected over time many fallen trichromes. Rather than letting them go to waste, these are soaked in a bucket of cold water. The liquid is then passed through a succession of bags with decreasing screen sizes which capture the trichromes, which are then pressed into shape and let dry. The result is called bubble hash, due to the bubbling which occurs when it is heated for smoking. This bubbling is due to its purity, as adulterants tend to cause hash not to bubble. ^[7]

Hash Oil. Cannabinoids are soluble in some chemicals, notably butane and isopropyl alcohol. It is possible to take the leaves and stems of the plant, which are generally considered to be of low THC concentration, and immerse them in liquid butane. The butane is then captured through a filter, and evaporated. The resultant hash oil is often very strong in terms of THC content, and can be then smoked. It should be noted that butane is a highly toxic chemical that should not be eaten, and is also highly combustible. Since butane is heavier than air and will settle on the ground, hash oil is only made outdoors.

Strong grain alcohols, such as Everclear, can also be used to extract cannabinoids from the marijuana plant. The extraction process takes longer, but results in an edible product. Marijuana stems, leaves and buds can all be used. Strong grain alcohols evaporate very quickly. The resulting mixture can be eaten straight, mixed with food or even smoked. Many smokers prefer to dip cigarettes in the mixture, which allows them to smoke in public without detection. Contact with direct flame causes this liquid to lose its THC content. Smokers usually heat the liquid and inhale the heated vapors through a straw.

[edit] Alternative cultivation techniques

[edit] Hydroponic cultivation

Main article: Hydroponics

Hydroponic cultivation generally occurs indoors, although there is no practical obstacle to growing outdoors. In general, it consists of a non-soil medium which is exposed to a nutrient and water flow.

There are many types of hydroponic systems. If the nutrient solution floods the loose growing medium and recedes for aeration, this is an ebb and flow or flood and drain system. Systems that gradually drip solution onto the medium are drip systems. Systems that intermittently spray roots floating in air are called aeroponic systems. If aerated water runs down a channel lined with a film of rooting medium, this is a nutrient film technique system. A series of tubes intermittently running high flow nutrient solution into the tops of growing containers use a top feed system.

Hydroponic systems greatly increase aeration of plant roots, and increase control of nutrient uptake. Hydroponic systems are decidedly more difficult to operate for the amateur or hobby grower, as over-fertilization is common, because there is no soil to act as a nutrient buffer. For this reason, many growers now use coconut fibre as a soilless medium due to its high drainage and buffering capabilities, making it almost impossible to over-fertilize. Additionally, if a hydroponic system fails, the crop has a high probability of dying as the roots rapidly dry out (this is especially true of aeroponic systems). However, properly operated hydroponic systems, with other factors at an optimum, have been proven to outperform soil under the same environmental circumstances.^{[citation needed]}

In marijuana culture, some believe that hydroponically cultivated marijuana can have fewer byproducts in the resultant smoke and ash, providing for a cleaner and healthier smoke.^{[citation needed]} Of course, the veracity of such claims is suspect, as with proper pre-harvest flushing, and post-harvest drying and curing, there would be nothing to indicate an inherent difference in harmful content between soil and soilless mediums. This itself is controversial, as many growers/botanists believe any excess nutrients are broken down into sugars during the drying and curing processes, effectively killing the plant by starving it of nutrients.^{[citation needed]}

[edit] Organic cultivation

Organic (a substance containing a carbon molecule, and that is or was a living organism), may be a misnomer when applied to cultivation of cannabis, though it is similar to the organic food movement in recent times. It is superficially similar to the hydroponic methods, with the exception of tending towards soil and nutrients which are derived from organic sources. In general, these sources are items like guano. The use of soil (generally in buckets or heavy duty plastic bags) makes for a more natural cultivation process. However, the composition of the "organic" nutrients is monitored by the manufacturers, and is usually printed on the container. For this reason, the supposed organic cultivation of cannabis, especially indoors, resembles other controlled cultivation methods where the intake of the plants is closely monitored. Organically grown marijuana gives a smoother smoke, supposedly because the flowers are free of heavy metals and other impurities that may occur in chemical fertilizers.^{[citation needed]} However, if done right, a plant grown through the hydroponic method will yield more than the same plant grown with the organic method.^{[citation needed]}

[edit] Screen of green

One of the techniques used in the cultivation of cannabis is referred to as screen of green or SCROG because it involves training the plants to adapt to a wire mesh (similar in technique to an arbor). This assures near-equal light exposure to all the plants. This is a system particularly adopted by hobby growers with limited height in their grow-area. Commercial grow operations use it less because it is very labor intensive to train the plants to the screen, and requires an extended vegetative phase. This method also causes stems to grow much stronger and be able to bear more fruit.^{[citation needed]}

[edit] Sea of green

In contrast to the "Screen of Green" methodology, Sea of Green (or SOG) growing depends on the high density of plants (as high as 60 per square meter) to create uniformity in the crop. In this technique, which is often grown in hydroponic media, only the colas of the plants are harvested. In the image to the right, geometric containers are visible. Such containers are used to enforce the geometric distribution of flowers and plant material, as well as their exposure to lighting and atmosphere. Sea of green is popular with commercial cultivators, as it minimizes the amount of time a plant spends in vegetative stage, and allows very efficient light distribution, keeping the plants much closer to the lights than when grown to full size. However the amount of buds those plants produce are much smaller compared to a properly grown plant (usually just under 1 ounce).^{[citation needed]}

[edit] Sinsemilla

Sinsemilla (literally, "without seeds" in Spanish) refers to removing male plants from the grow environment before they have a chance to fertilize the females. The resultant cannabis contains more psychoactive compounds known as THC. The amount of THC in sinsemilla is considerably more (14% Compared to 4%) in comparison to cannabis that has been grown in a pollinated environment, because the production of seeds requires an immense amount of energy, and if left unpollenated a female plant will divert all her energy to calyx production in an effort to catch pollen. This is especially desirable, as the calyx is where the highest concentration of trichomes exists, and the more densely packed a plant is with calyces, the greater psychoactive effect that plant will likely have.

Thus, sinsemilla is more expensive to purchase than cannabis with seeds, as the purchaser is actually receiving more psychoactive substance. Potent sinsemilla is especially important to medical users, to minimize the amount of cannabis they must consume in order to be afforded relief. Cannabis with seeds is generally considered to be of inferior quality and/or grown with inferior technique. A common term for seeded, or otherwise low-quality, cannabis is schwag.^{[citation needed]}

[edit] Genetics and breeding

[edit] Selection of mother plants

An important factor in cannabis cultivation is selecting the best genetics for one's crop. This is frequently done by selecting one or more known strains, or strains with preferred genetics (in the case of marijuana, one might use seeds from a batch that was particularly enjoyed), and then growing a number of the seeds to find out which exhibit the characteristics most desirable to the cultivator.

Plant characteristics which are generally selected for include:

• Overall yield
• Time to fruition
• Resistance to pests
• Geometric traits (uniformity, compactness, flower density, etc)
• Color
• Flavor and/or aroma
• Appeal to end buyer (known as "bag appeal")
• Psychoactive Qualities

When a cultivator has decided which plant or plants exhibit the most desirable traits, a cutting is taken and grown to maturity but never allowed to flower. This plant is referred to as a mother, and can be kept for a number of years, producing thousands of clones genetically identical to the mother.

[edit] Feminized seeds

It is possible to use a combination of cloning and "shocking" plants to get them to produce feminized seeds. A clone will retain the same sex throughout its life, so if a female plant is cloned, its clone children will also be female, precluding reproduction.

It is possible to use very erratic lighting, or several days of no light at all, to shock a plant into turning into a hermaphrodite. Such plants have both male and female sex organs. After doing this, a hermaphrodite can reproduce with one of its clone children. This will yield sometimes in excess of 90% female plants, if the process is begun with a female. This makes the cultivation of sinsemilla from seed much easier. It is very difficult to produce reliable feminized seeds, however, as plants grown from feminized seeds demonstrate a greater tendency towards hermaphrodism.

[edit] Hybrid vigor

When crossing two strains of cannabis (or two of any plant), the resultant hybrid may possess what is called hybrid vigor. In general, this produces a plant which is healthier, stronger, or quicker growing than its predecessors. Sometimes, in the case of a plant which has been brought back from fruiting (fruition, as mentioned above), it may be beneficial to cross it back with another (close) relative, in the hopes that it will become invigorated.

Caution should be exercised, as one does not always attain a beneficial cross with hybridizing.

[edit] Cloning from cuttings

Like many plants, cloning of cannabis is possible though technically more laborious and somewhat challenging, due to the cleanliness required. The process itself is quite similar to the cloning of most other plants and involves rooting branch cuttings from donor plants.

Cutting are taken and the large leaves near the bottom of the plant are removed to minimize transpiration and the cutting is allowed to heal before being immersed in a a dilute solution of high phosphorus fertilizer (10-50-10). While keeping the cutting under the solution, a 45 degree cut is made to the "root" end of the cutting using a clean knife that has been sterilized with bleach. This procedure prevents air bubbles from forming in the xylem of the stem which may affect water and nutrient uptake. Using a clean knife minimizes infection risks, which can wipe out a number of clones quickly.

Rooting hormone gels or powder mixes are then applied to the cut to promote root growth and inhibit fungal infection. Growth trays with good drainage, filled with a moistened loose organic medium such as vermiculite and perlite is used allow the cuttings to root. Another option is to start clones in rockwool cubes, which allow transplanting without disturbing fragile root systems. Sterilization of the medium by baking or steaming is preferred. The cuttings are then inserted into the loose medium, and then must be continuously kept in a dim, moist, and humid environment under a plastic covering for up to two weeks such that they have a chance to heal and form roots. During the first week the cutting should not be watered unless the medium becomes dry, and even then, it should be done with discretion. A weak solution of high phosphorus fertilizer, usually sold as flowering promoting fertilizers, can be applied to the cutting in the second week since the phosphorus helps the rooting process, which will help in producing strong plants.

If performed correctly, the cuttings should stay green during their rooting time, and condensation should appear on the plastic coverings for the cuttings, which indicates proper humidity. Drooping and browning of the cuttings likely indicate too much sunlight, too little humidity, cutting rotting in sitting water, or unsanitary cloning conditions.

[edit] Detection and the law

As cannabis and its cultivation is illegal in most parts of the world, considerable resources and effort are committed to both interdiction and counter-interdiction of cultivation.

[edit] Outdoors

Outdoor cultivation is common in both rural and urban areas, with outdoor cultivators tending to grow sativa-based strains for their better response to sunlight and reduced emission of odours.

Cannabis plants blend in easily with other plants and are unidentifiable by all but the most observant. Often simple camouflage techniques can avert detection, such as mixing cannabis plants with other bushy, leafy species. Plants started outdoors late in the season do not grow as tall, attracting less attention when placed next to plants of similar or taller stature. Even tall plants grown among trees can be almost invisible in their camouflage.

A common technique used by many outdoor growers is to dig a hole and put a potted plant in it. This can reduce a plant's height by at least a foot, reducing visibility to neighbours, visitors and guests. Also, some growers top the plant when it is only 12 inches (30 cm) high, and grow the 2 tops horizontally along a trellis. When using this technique, it is unlikely the plant will grow to be over 3 feet (1 m) tall.

Law enforcement agencies often monitor certain wider areas, particularly areas of countryside with a significant history of outdoor cannabis cultivation. In helicopters, they use infrared cameras and other equipment that can detect cannabis by measuring the heat and reflective signature of the vegetation below. Cannabis has higher reflectivity at certain wavelengths than other rural crops, such as corn. Law enforcement agencies have found that the use of this technology has become necessary in their detection efforts because many growers hide cannabis among other plants, making detection with the naked eye difficult even from the air. These techniques are effective and difficult to defeat because a plant's reflective signature is difficult to change or mask.

[edit] Indoors

Indoor growing has become increasingly common over the past decade, in part due to increased availability of equipment, seeds and instructions on how to cultivate. So-called grow-ops (growing operations) are seen by many marijuana enthusiasts as a much cheaper way in which to gain a steady, higher-quality supply of cannabis. On a larger scale they have proven a viable commercial venture, with some law enforcement agencies finding grow-ops large enough to yield several kilograms of marijuana. More expansive grow-ops, however, are generally more susceptible to detection than smaller operations.

Since individual grow light power generally ranges from 250 watts to in excess of 1000 watts and remain lit for a long time each day, differences in utility bill costs are a significant security issue. It is not uncommon for power companies to work with law enforcement if they witness significant increases in power usage relative to a household's previous electricity costs. Employing energy saving methods is a common way to alleviate this, for instance; switching off light bulbs when leaving rooms, purchasing energy efficient appliances, using TV's or computers less, buying lower power light bulbs and so forth.

Some strains, especially cultivars of C. sativa subsp. indica, can give off strong odors as they grow, resulting in detection. Growers frequently use carbon scrubbers in conjunction with ventilatiion in order to control odors. This typically involves forcing air from the grow room through a device containing activated carbon, before being vented outdoors. Others use an ozone generator. Ozone reacts with odor molecules in the air, permanently eliminating them. However, ozone can build up to levels that may be hazardous both for the grower and the plant. As a last resort, strong air fresheners are used to control smells as well as keeping windows firmly shut. This is a risky method, as the smell of air fresheners may often arouse suspicion by police officers. Checking outside to see if any smells are emanating from indoors is often a necessary precaution, as many growers become acclimatized to the smell, and fail to realize just how pervasive the odor may be. Many store plants in more isolated areas such as a basement or attic to prevent smell detection. Another less common solution is to simply grow a strain which possesses a weaker odor.

Storing plants and lights away from windows and areas which may be seen by visitors is also a common practice, as is keeping the entire grow op in an attic or basement. Some growers, finding this impractical, may cover their windows with light-resistant materials. This can solve the problem of escaping bright light but may arouse suspicion amongst neighbours and local residents.

Many cultivators face detection by fire. Fires normally originate from faulty electrical equipment or wiring. Shoddy fixtures and sockets, improperly grounded equipment, and faulty circuit breakers are some of the most prevalent causes. Due to the large amount of electricity needed for large-scale cultivation, old or damaged wiring is prone to melt and short. Some commercial growers resort to power theft in order to hide electricity usage and many do not take precautions to ensure that their connections are safe. Many growers adapt light cycles so that the lights are on when they are home and off when they are away.

Another fire hazard is plants making contact with hot HID bulbs. Growers using fluorescent bulbs with reasonable air circulation do not have this problem.

Word of mouth can of course be as much a threat to growers as any of the above issues. Often, a few sentences of conversation overheard can result in a tip-off and thus speedy detection. It is for this reason many growers keep are reticent about their cultivation.

[edit] See also

• How-to Guide to Cultivation (located in wikibooks)

Cannabis resources (edit)

Use: recreational drug, pharmaceutical drug, spiritual, culture, 420, health issues, legal issues, cultivation, pipe smoking

Preparations: bhang, hashish, kief, shake, hash oil

Smoking: blunt, bong, chillum, dugout, gravity bong, hookah, joint, shotgun, smoking pipe, steamroller, rolling papers

Vaporization: vaporizer, knifers

Food: cannabutter, dope cake, Ganja goo ball, hash cookie, Green Dragon, Leary biscuit, cannabis brownie, Cannabis tea

[edit] References

1. ^ ^{a b} Hillig, Karl W., Paul G. Mahlberg (2004). "A chemotaxonomic analysis of cannabinoid variation in Cannabis (Cannabaceae)". American Journal of Botany. 91: 966-975.
2. ^ Small, Ernest (1975). American law and the species problem in Cannabis: Science and semantics.
3. ^ ^{a b} USDA, NRCS (2006). The PLANTS Database. National Plant Data Center. Retrieved on 2006-11-01.
4. ^ Small, E., H. D. Beckstead (1973). "Common cannabinoid phenotypes in 350 stocks of Cannabis". Lloydia 36: 144–165.
5. ^ The CO₂ enrichment guide
6. ^ [1]
7. ^ [2]

• Cervantes, Jorge. Indoor Marijuana Horticulture. Van Patten Publishing, 2001. ISBN 1-878823-29-9
• Clarke, Robert Connell. Marijuana Botany. Berkeley: Ronin Publishing, 1981. ISBN 0-914171-78-X
• Green, Greg. The Cannabis Grow Bible. San Francisco: Green Candy Press, 2003. ISBN 1-931160-17-1.
• Herer, Jack. The Emperor Wears No Clothes: The Authoritative Historical Record of Cannabis and the Conspiracy Against Marijuana. Ah Ha Publishing Company,2000. ISBN 1-878125-02-8
• Starks, Michael. Marijuana Chemistry: Genetics, Processing & Potency. Ronin Publishing, 1990. IBSN 0914171399

[edit] External links

• Seedbank Update - The authority for seedbank market research.