What is Cannabis
Classification of cannabis
In the scientific classification, hemp and marijuana belong to the family Cannabaceae. As such, both are considered cannabis.
In the United States, the term "hemp" is used to describe a cannabis plant that produces no more than 0.3 per cent THC, which is the molecule responsible for the euphoric effects associated with medical and adult cannabis. The classification does not take into account other cannabinoids. Therefore, if a plant produces 20% CBD and only 0.29% THC, it is still legally considered hemp.
Hemp has many uses; its fibre can be used for canvas, paper, rope and other textiles, it is an incredibly effective bioremediator (it removes toxic substances from the soil), and it is increasingly used as a building material and biofuel. Hemp seeds have long been used in many crops for their nutritional benefits for animals and humans.
Many laws have been created based on this definition of hemp. It is the level of THC produced by the plant variety that differentiates it from the intoxicating variety of cannabis, "marijuana", and allows its legal classification as a staple crop.
"Marijuana" or "drug cultivars" are the terms used to refer to the variety of cannabis that produces more than 0.3% THC. There is a staggering diversity of molecules that plants in this legal category are capable of producing. These include the cannabinoids CBD, CBG and CBC, which are valued for their medicinal properties.
In fact, cannabis produces over 100 unique cannabinoids that mimic compounds produced in the human body. These plant-derived cannabinoids (phytocannabinoids) can replace endogenous cannabinoids when the body has a deficiency in its endocannabinoid system.
Cannabis cultivars (commonly known as strains) also produce terpenes, the aromatic molecules that are the main ingredient in the essential oils produced by many plant species. Different cannabis cultivars have unique terpene profiles, which determine the aroma and flavour of the flower. Although research is still ongoing, we know that terpenes can enhance or modify the psychological and physiological effects of phytocannabinoids. When whole plant cannabis is consumed, there is a unique interaction between all these molecules that appears to have a greater medical benefit than the consumption of individual molecules.
Cannabis is a versatile crop that can grow in many climates. It is an annual plant that loves the sun and grows in a variety of conditions, depending on the cultivar. Cannabis can be male or female, with reproductive organs, male staminate (stamen) and female pistillate (pistils), usually present on different plants. In the presence of male pollen, the female begins to produce seeds.
Cannabis grown from seeds begins with germination, a process by which the seed is "germinated" and then fed into the raw material, which can range from soil to rock wool. At this stage, the plant is considered a seedling.
For greater uniformity, some growers start with clones, which are clippings of a cannabis "mother plant" that has been maintained in a vegetative state. Clones are genetic copies of the mother plant and will show more predictable growth and flowering patterns, as well as cannabinoid and terpene profiles, if grown under the same conditions.
Cannabis is usually grown in soil or hydroponically indoors or outdoors. A number of factors influence the successful growth of cannabis, including climate, nutrients used, water quality and uniformity of irrigation.
The light cycle to which a cannabis plant is exposed during its life has a marked impact on its growth. The number of hours during the day that cannabis is exposed to light will determine the type of growth of the plant: vegetative (engaged in growth functions) with more than 16 hours of light and flowering (engaged in reproductive functions) when light is limited to 12 hours.
Once cannabis has been successfully grown and flowered, it is ready for processing. The flower has to be dried and dried for consumption or production of concentrate. The freshly harvested plant can also be sent immediately for processing for the production of concentrate. Once the cannabis has been processed as desired, it is ready for consumption.
Behind each cartridge of joint, edible or oil is a cannabis plant with several equally distinct parts.
Cannabis grows in a variety of climates around the world and can be used in many applications, from rope, canvas and paper to medical and adult consumption. The plant is part of the Cannabaceae family, which also includes hops. Each part of the plant has a purpose and some parts are more important than others. Below is a description of each part of the plant.
Anatomy of the cannabis plant
The flowers of the female cannabis plant can be identified by their small teardrop-shaped structures, which consist of a pistil attached to a bract. Most of the flowers are covered with a frosted layer of trichomes.
The main "flower", composed of small female flower clusters at the end of the stem of a plant.
The small leaves that surround the reproductive cells of female plants. When a female plant is exposed to male pollen, the bract surrounds and protects the capsule.
Resinous appendages found on the surface of the cannabis plant that contain the plant's cannabinoids, flavonoids and terpenes. Trichomes give the cannabis buds a crystalline shine and a sticky feel.
Point of intersection of stem and leaf. The nodes may contain one or more leaves.
Large protruding leaves that appear along the entire length of the plant and are essential for the plant's photosynthesis.
Small leaves found in cannabis colas that are usually cut from the flower after harvest. Called "sugar leaves" because the high volume of trichomes found on the leaves resembles sugar. Sugar leaf trimmings can be used to make hashish or concentrates.
The reproductive system of female flowers consists of a single ovule with two protruding stigmas.
The fine hairs that extend from a female flower to catch the male pollen. They are commonly and wrongly called Pistils.
The main support structure of the plant that carries fluids and nutrients from the roots to the rest of the plant and provides a base to give the leaves access to the light they need to facilitate their growth.
Relatively few cannabis users have handled an entire cannabis plant, let alone been able to identify its individual parts. As the cannabis industry develops, the distance between the raw plant and the end user inevitably increases. Collectively, we consume thousands of foods and beverages without thinking about the corn crops that were harvested to make them.
But knowing where one's food comes from has become a growing trend among U.S. consumers-a trend that is likely to spread through the cannabis trade. If you want to stay in touch with the origins of your favourite cannabis products, knowing the ins and outs of the plant at the heart of the industry could be a good place to start.
Cannabis trichomes - How cannabinoids, terpenes and flavonoids are made
Trichomes are important. Why is that important? Because they deliver the goods
Although you may not know exactly what it is, you have probably noticed the small hairs that cover the cannabis plant, giving it a crystalline sheen and a sticky feel. These glandular hairs are called trichomes, and they are responsible for virtually everything you love about cannabis.
Trichomes are glandular hairs found on the surface of the plant that are responsible for producing the cannabinoids and terpenes of the cannabis plant. Trichomes contain resin glands that produce terpenes, flavonoids, THCA, CBDA and other phytocannabinoids for which cannabis is known.
The crystalline sheen and sticky feel of cannabis buds is caused by heavy accumulations of trichomes. Although they are most visible to the naked eye on the cannabis flower, trichomes can also be found on the leaves and stems of the plant.
Trichomes Bulbous, stalked capitulum
There are two main categories of trichomas: glandular and non-glandular. The glandular type produces cannabinoids while the non glandular type does not. In glandular trichomes, there are three main types: bulbous, sessile capitular and stalked capitular. Non-glandular trichomes are called cystolites.
Bulbous trichomes are tiny bulbs that dot the surface of the plant. They cannot be seen without a microscope. While their production of cannabinoids is still in question, they add a crystalline luster to the cannabis plant and add to the stickiness of the flower. Bulbous trichomes are not limited to particular areas of cannabis; they are distributed evenly over the entire surface of the plant.
Trichomes of Capitate Sessile are more abundant than bulbous trichomes, but are usually only visible under a microscope. Like bulbous trichomes, sessile capitate trichomes have large bulbs, but with a more classic "mushroom" type structure. This type of trichome is mainly found on the underside of sugar and fan leaves.
Stalked trichomes are mushroom-shaped and contain a large bulb at the head of the stem. These are the largest and most abundant trichomes in cannabis and the shape that consumers are most familiar with because they are easily visible to the naked eye. The petiole trichome is found mainly on the surface of cannabis flowers and is rarely seen on sugar or fan leaves.
Capturing the petiole trichome
How are cannabinoids created in the trichome?
Cannabinoids, terpenes and flavonoids are produced inside trichome cells by biosynthesis, in which enzymes catalyze a series of chemical reactions to produce complex molecules from simple (small) molecules. A quick overview: Cannabinoids produced by the cannabis plant, or phytocannabinoids, interact with receptors in our body to produce many psychotropic and therapeutic effects. Terpenes are compounds responsible for the aroma and flavour of cannabis and help the cannabinoids produce the desired effects. Flavonoids are similar to terpenes in that they contribute to the aroma and flavour profile of a plant, but they can offer their own therapeutic effects.
The three basic steps in cannabinoid biosynthesis are binding, prenylation and cyclisation. At the molecular level, the activity is as follows: Nanoscale macromolecules called enzymes bind to one or two small molecules (substrates), attach the substrates to each other (prenylation, catalytic chemical conversion of substrates), and then pass the small molecule (transformed substrate) on an assembly line to another enzyme that processes it, making sequential changes to the small molecule (cyclization). Think of enzymes as biological nanomachines that use chemical energy rather than mechanical energy to build structures. Enzymes have inspired many studies in nanotechnology, biology and other fields.
The following figures illustrate some of the molecular structures involved in the biosynthesis of cannabinoids. In these figures, each line is a bond between atoms. When two lines meet at a point and no letters are written, the atom is, by default, carbon. Oxygen and phosphorus atoms are explicitly indicated. Hydrogen atoms are only attracted when they are bonded to oxygen or the aromatic ring, they are not attracted to alkyl chains. The curved arrows pointing from atom to atom indicate that a new bond is formed between these atoms during the reaction, they also indicate the movement or exchange of the electrons that make up a bond. Not all steps are displayed, so there are bonds that break and by-products formed that are not shown.
The three basic steps of cannabinoid biosynthesis are binding, prenylation and cyclisation. At the molecular level, the activity is as follows: Nanoscale macromolecules called enzymes bind to one or two small molecules (substrates), bind the substrates together (prenylation, catalytic chemical conversion of substrates), and then pass the small molecule (transformed substrate) on an assembly line to another enzyme that processes it, making sequential changes to the small molecule (cyclization). Think of enzymes as biological nanomachines that use chemical energy rather than mechanical energy to build structures. Enzymes have inspired many studies in nanotechnology, biology and other fields.
The following figures illustrate some of the molecular structures involved in the biosynthesis of cannabinoids. In these figures, each line is a bond between atoms. When two lines meet at a point and no letters are written, the atom is, by default, carbon. Oxygen and phosphorus atoms are explicitly indicated. Hydrogen atoms are only attracted when they are bonded to oxygen or the aromatic ring, they are not attracted to alkyl chains. The curved arrows pointing from atom to atom indicate that a new bond is formed between these atoms during the reaction, they also indicate the movement or exchange of the electrons that make up a bond. Not all steps are displayed, so there are bonds that break and by-products formed that are not shown.
The precursors of all naturally occurring cannabinoids, geranyl pyrophosphate and olivetolic acid, are produced by a complex series of biosynthetic reactions. Geranyl pyrophosphate and olivetolic acid bind to each other using a prenyltransferase enzyme called GOT, creating the first cannabinoid, CBGA (see Figure 1). CBGA contains a carboxylic acid group whose molecular formula is COOH and, due to the presence of this acid group, an "A" is placed at the end of CBGA. This is the case for other cannabinoids whose acronym ends with the letter A (THCA, CBDA, etc.). The carboxylic acid groups spontaneously separate from the cannabinoid structures in the form of carbon dioxide (CO2) when heated. This process is called decarboxylation, after which the designation "A" is lost. For example, decarboxylated CBGA becomes CBG. It is considered a degradation process because it does not require enzymes and occurs after the plant is harvested. Cannabinoids of the CBG type have a ring in the molecular structure, which is the aromatic ring that comes from olivetolic acid (see Figure 1).
CBGA is therefore the first cannabinoid formed from a biosynthetic reaction that brought two smaller pieces together - it is also the precursor of all other natural cannabinoids. The CBGA is then cyclized to THCA, CBDA or CBCA via enzymes called THCA synthase, CBDA synthase and CBCA synthase. The presence and relative amounts of the specific enzymes are what controls which cannabinoid is the main product of each particular strain, and each particular cell. Remember that CBG-type cannabinoids have only one ring in their structure. After cycling reactions, the cannabinoids THCA, CBDA and CBCA have more rings in their structure (see Figure 2).
For THCA, two new rings are formed by the creation of two new covalent bonds, a carbon-oxygen bond and a carbon-carbon bond. The enzyme CBDA synthase catalyzes a reaction that creates a new carbon-carbon (C-C) bond at the same position as the C-C bond formed in THCA, but without the new C-O bond, thereby forming CBDA. The formation of CBDA occurs by the formation of a carbon-carbon-oxygen bond at a different position in the molecule than the carbon-oxygen bond formed in THCA. Compounds with two rings fused to each other, as in CBCA and CBDA, are said to be bicyclic. Thus, THCA, ADBC and CBCA are produced by biosynthesis.
Major cannabinoid biosynthesis
When the cannabis flower is dried and cured properly, the most important cannabinoid will be the acid form of the cannabinoid (THCA, CBDA, CBCA or CBGA). When smoked or cooked into edible products, these molecules decarboxylate (decarboxylated forms can be produced to a small extent by biosynthesis and during drying, but the acidic forms are the main product). The decarboxylation products are Δ9-THC, CBD and CBC (see Figure 2).
As you can see, the effects of cannabis are the result of complex developments of cannabinoids, flavonoids and terpenes that take place in the trichomes of the plant.
The difference between Indica and Sativa. Do they matter?
The terms Indica and Sativa have probably dictated every decision you've made about cannabis. If you are a novice, moderate or experienced cannabis user, the first question you probably ask yourself every time you shop is whether you want the "body high" of Indica, the "cerebral rush" of Sativa, or the varied effects of a Hybrid.
Each cannabis variety, or cultivar, has its own shape, colour, aroma profile and effects. What we may not know is how often we limit the scope of our cannabis consumption by forcing each flower into one of two - or sometimes three - ambiguous categories.
This is not to say that Indica and Sativa are completely irrelevant terms. Producers use them to classify plants according to their growth characteristics and resulting chemical profiles, which helps retailers market cannabis by categorizing the effects on consumers. In other words, Indica and Sativa are always there because they are always good for something.
Conventional wisdom is rarely unfounded, but that does not mean it is always reliable. So let's delve into the Indica vs. Sativa controversy - let's find out where these terms came from, how we use them today, and whether they are still valid in our current cannabis landscape.
Where did Indica and Sativa come from?
Together, Indica and Sativa have been the basis of the cannabis lexicon since the mid-1700s. In 1753, Swedish botanist Carl Linnaeus identified psychoactive cannabis plants as Cannabis sativa in his book Species Plantarum, and 32 years later, French biologist Jean-Baptiste Lamarck identified Cannabis indica as a different species by observing the physical characteristics of Indian plants. Lamarck argued that the plants of C. indica had narrow, dark green leaves compared to the light, narrow leaves of C. sativa.
In 1930, the Russian botanist Dmitrij Janischewsky identified Cannabis ruderalis as the third subspecies. This time it was not the result of unique physical expressions, but rather of unique features in the flowering cycle of the plant. Janischewsky noticed that while most cannabis plants begin to flower due to changing sunlight, ruderalis plants automatically begin to flower between 20 and 40 days after germination.
Now you probably haven't heard your local budtender suggest a new "Ruderalis" variety. That's because botanists have never quite agreed on a definitive cannabis taxonomy.
Another turning point in our current taxonomy came in the mid- to late 1970s, when American biologists Loran Anderson and Richard E. Schultes argued that there were three species of cannabis: C. sativa, C. indica and C. ruderalis. Somewhat different from Linneaeus and Lamarck, Anderson and Schultes characterized a distinction between plants based on their ratio of the cannabinoids THC and CBD. They observed a difference between high THC cultivars with low CBD (C. sativa), those with high THC and CBD (C. indica) and those with high CBD/THC ratio (C. ruderalis).
In 1976, when Schultes and Anderson made their claims, Ernest Small and Arthur Cronquist argued that there was only one core species of cannabis, which they called C. sativa. Human intervention, they argue, subsequently created two subspecies: C. sativa (low THC hemp) and C. indica (high THC cannabis grown for intoxication).
Today, we continue to make discoveries about cannabis that are reshaping our taxonomic framework. Since the mid-2000s, botanists have turned away from the taxonomy of Small's and Cronquist, arguing that the Sativa and Indica subspecies may have preceded human intervention. We also began to recognize the importance of terpenes in shaping the cannabis experience - something that previous taxonomists had never considered.
It is important to note that these terms were created for botanists, not pharmacologists. Botanists use these terms to classify plants on the basis of common characteristics and not on the basis of their effects on the human body.
How are these terms used now?
Almost immediately after their creation, the terms Indica and Sativa were used to identify cannabis plants based on the shape and size of the main leaves and the amount of fibre they produce. Today's growers use them for much the same purpose - to separate Indica and Sativa plants according to their growth characteristics and physical composition.
If the Indica and Sativa taxonomy is for everyone, it's for growers. However, unsuspecting consumers may find them a bit misleading. Human intervention has radically changed the chemical composition of the cannabis plant since the days of Linnaeus and Lamarck. The effects of Indica and Sativa plants in the 1700s probably corresponded more closely to their physical classification than they do today.
Differences between Indica and Sativa
The real difference between today's Indica and Sativa plants lies in their observable characteristics during the growing cycle. Indica plants tend to grow short with thick stems and large dark green leaves. They also have short flowering cycles and grow well in cold climates and short seasons. Sativa plants have longer flowering cycles, do best in warm climates with long seasons, and generally grow taller with narrow, light green leaves.
Over the last 50 years of cannabis cultivation, crossbreeding has been the name of the game. As a result, there is virtually no "pure" Indica or Sativa left. Every flower you've been in contact with is probably some kind of hybrid. Classifying a cultivar or strain as Indica or Sativa usually means that it switches to one side or the other of the Indica/Sativa spectrum.
Indica vs. Sativa effects
The "Indica vs. Sativa" framework has been controversial, and rightly so. When researching cultivars online, you may come up against the same expressions to describe Sativas ("cerebral", "heady", "exhilarating", "energizing") and Indicas ("relaxing", "sedative", "full-bodied", "couch lock", "stone"). It is always perfectly valid to describe the effects as "Sativa-like" or "Indica-like", provided you remember that Sativa or Indica-like effects do not necessarily coincide with the Sativa or Indica lineage of a plant.
That's where the hybrids come in. You've probably noticed how hybrid cultivars have become as important as Indicas and Sativas, if not more so. This is a sign that cannabis marketing is catching up with reality. All modern cultivars are technically hybrids, but the plants we officially classify as hybrids are intentional crosses of Indicas and Sativas, designed to produce specific qualities and effects. Budtenders often recommend hybrids for their highly specialised effects, flavours and aromas.
Hybrids certainly present a more nuanced taxonomic reality, but they do not provide a label that adequately indicates the effects a user can expect from a cultivar - especially as we recognise how our bodies react differently to cannabis. Have you ever settled down to relax with an Indica, only to find yourself in a high-energy brain mist? Or maybe you've tried a Sativa-dominant hybrid that you've heard is great for productivity and ended up in a prolonged, body-filled couch lock? The truth is that you can't always rely on your body to receive Indica or Sativa effects from an Indica or Sativa flower. You and your friend can smoke the exact same bud and have two equally distinct experiences.
Smoking a joint
How do Indicators and Sativas change your high?
The paradigm "Indica vs Sativa = relaxation vs exhilaration" is clearly outdated, if not totally inaccurate. So where does that leave us? What relevance, if any, do the terms Indica and Sativa have, and what effect will they have on your high?
The answer is not as desperate or as clear as you might think. Each strain produces an effect as individual as its end user, but that doesn't mean you can't make truly informed decisions about which cultivars you're going to try.
The effects you feel from a particular strain of cannabis are much more directly related to a specific set of compounds - specifically, cannabinoids and terpenes - and how they affect you as an individual. THC - the dominant compound in cannabis - is just one of the many cannabinoids found in the cannabis plant. Each cultivar has its own cannabinoid makeup and accompanying effect. Terpenes - the organic compounds responsible for the flavours and aromas of a plant - greatly influence the character and effect that a cannabis plant will produce. The Indica and Sativa labels were established centuries before we realized how integral terpenes were to the overall effect of a given cultivar.
Knowing the difference between Indica-like or Sativa-like effects is a great starting point for deciding which products to use, but you'll be able to make much more informed decisions once you start paying attention to the cannabinoid and terpene content. As always, knowledge comes with experience. Every body reacts differently to outside influences. All it takes is experience and the right information to know what works for you. In the end, you are your best resource in determining which cannabis products will produce the effects you are looking for.
What's in a strain name?
Separating fact and fiction in a strain name
Every two days a new cannabis variety with a new name appears. The names of marijuana strains have become confusing, largely because they carry only a marketing message.
Some strains are patented and their genetics have been protected by those involved in the creation of the plant. You can only get Mega Wellness from one authentic grower, for example. These growers keep tight control of their stocks and can check the markets where their products can be found. But the name "Mega Wellness" alone tells you nothing about the effects you can expect. You can only determine this if you know the grower well. In other words, the names of the marijuana strains alone do not reliably mean effects. The Weedmaps verification system helps you to discover authentic brands with verified products. This helps people make better buying decisions instead of just shopping by strain name.
Let's take OG Kush as an example. It is one of the most popular strains in Southern California and can be found in almost every clinic, but the effects from clinic to clinic can be completely different. This is mainly due to the fact that growing conditions from one grower to another can vary and alter the resulting composition of cannabinoids and terpenes. "Annie" OG Kush can be radically different from "Johnny" OG Kush. So if you want the same experience, make sure you buy it from the same grower or brand.
Due to the legal landscape of cannabis around the world, most of the strains found today have been hybridized through selection by breeders. Landrace strains are the exception. They are cannabis cultivars that have never been crossed and have evolved naturally through prolonged exposure to the elements in their natural environment. Known landrace strains originate from Afghanistan, Pakistan, Jamaica, Mexico, Africa, South and Central America, and Asia.
Where and how cannabis is grown, harvested and processed contributes directly to the composition of the terpenes and cannabinoids present in the final product. If you are looking for consistent quality, it all starts with the source (the brand) - not the strain. So it's important to explore your options to find the right flower for you based on what it contains and who made it, rather than the strain name alone.
The names of marijuana strains can be inconsistent and have been developed primarily to add commercial appeal, although some value can be derived from them. For example, you can expect a fresh, lively aroma from the California Orange, Tangie and Sour Tangie varieties, which all share a citrus scent. The Sour Diesel, NYC Diesel and Blue Diesel varieties all have a degree of gasoline-like pungency, as suggested by the word "diesel" in their names. Strain names may lack uniformity and general structure, but may give an indication of some strain characteristics.
Grass or resin, what's the difference?
Although hemp and marijuana are two varieties of cannabis, there is a difference between them. The differences between these cannabis varieties are mainly evident in the use that is made of each plant. These differences are also documented in the language, laws and regulations that apply to each variety. In this introduction to hemp, we will analyze the anatomy, history, use and legality of hemp to understand not only what distinguishes it from marijuana, but also what makes it such a viable and versatile product.
What is hemp?
Hemp is a variety of Cannabis sativa L. Hemp is a dioecious plant, which means that it can be separated into male and female plants. For more than 10,000 years, hemp plants have had a wide variety of uses for fibre (from the stems of the plant) and protein (from the seeds). Hemp fibres can be used to make countless household items, including paper, clothing, upholstery, rope, food and building materials.
Cannabis hemp varieties do not produce large amounts of tetrahydrocannabinol (THC), the intoxicating cannabinoid of marijuana, but they are capable of producing non-toxic, drug-rich cannabidiol (CBD) in high concentrations.
Many countries differentiate between marijuana and hemp on the basis of the amount of THC produced per weight of dry plant. In the United States, industrial hemp is defined as "the plant Cannabis sativa L. and any part of that plant, whether growing or not, with a delta-9 THC concentration not exceeding 0.3 per cent by dry weight. The European Union has set the limit at 0.2 per cent, whereas in Great Britain the limit is zero, unless you have a cultivation permit to grow industrial hemp with not more than 0.2 per cent THC.
The whole hemp plant, from stem to seed, can be used to produce fuel and raw materials. For more specific applications, hemp can be divided into four categories:
Hurdes, or shives
Leaves and flowers
Can hemp make you high?
Hemp is not completely absent from psychoactive compounds, but that doesn't mean it will make you high. Hemp plants simply don't produce enough THC to have an intoxicating effect. CBD, although psychoactive, is a non-toxic cannabinoid and will not produce any form of euphoric high on its own. In other words, hemp has a lot of therapeutic potential, but you'll have to look elsewhere if you want to get high.
How are hemp varieties chosen?
Depending on the desired end product, hemp cultivars are chosen based on several factors, including :
Hemp oil content
Seed production per acre
CBD production, in particular, has become a major factor in recent years. As the CBD market continues to grow, more and more cultivars are also being selected for their CBD production and their unique aromatic profiles, or terpenes.
How is hemp used as a food product?
Hemp seeds are rich in protein, dietary fibre, vitamins and minerals. They contain an optimal ratio of omega-6 and omega-3 fatty acids for healthy consumption. A 2008 study also found that hemp protein is more digestible to humans than soy protein isolates (SPI) used in food products.
Hemp can be used as a food product in the form of raw hemp seeds or hemp oil. Hemp oil is pressed from the seeds to obtain a protein concentration. Both forms of hemp food products use hemp as a nutritional resource. Hemp seeds can also be ground into flour or mixed with water to create hemp milk.
What is the purpose of hemp fibres and leaves?
CBD oil is extracted from hemp leaves, flowers and branch ends. The CBD oil extracted from hemp can be used to treat a wide variety of diseases, hence the ever increasing popularity of hemp cultivation based on CBD.
Hemp fibres are mainly used for textiles, paper, building materials and other industrial products. Furs, or shives, are short woody fibres of hemp that are usually found inside the stalk. They are used to make hemp concrete, bedding, absorbent materials, particleboard, ceiling panels, compost and other industrial products. Bast fibres make up the outer part of the stem and are generally divided into three categories: primary fibres, or line fibres, secondary fibres and cable. They are categorized according to their strength and cell wall thickness, which will determine the strength and durability of the fibre and ultimately what it can be used for.
How is hemp processed?
Many types of processing techniques are used to transform hemp seeds and stems. The technique used depends on the purpose of the final product.
Hemp seeds can be eaten whole, or refined by being pressed or crushed to produce hemp oil and hemp flour. Hemp seeds are also peeled, or shelled, to make them more palatable. The remaining shells, which are rich in fibre, can also be used to make flour.
Hemp stalks are treated by decortication, a multi-stage method to remove long fibres from the rest of the plant. The steps followed during the intermediate treatment period include:
Hemp stalks have a hard cell tissue that forms their surface and must be dissolved by a process called retting. There are three modes of retting:
Field Retting: Cut the hemp plants and place them in the field for four (4) to six (6) weeks, turning them periodically. During this time, any bacteria on the surface of the plant will break down the outer layer of the stem. Wet stems are then dried.
Water rusting: Stems are dried immediately after harvest and then placed in water for a few days. The water is used to soften the outer layer of the stems and to promote the growth of additional bacteria, which helps to speed up the process.
Chemical Retting: Use acids, bases and special enzymes to break down the compounds that hold the strong bast fibres together.
All wet stems must be dried.
Chemical Retting: Use acids, bases and special enzymes to break down the compounds that hold the strong bast fibers together.
All wet stems must be dried until they have less than 15% moisture. Any amount above 15% can potentially harbour and promote the growth of fungi and bacteria. If the stems become too dry, which means less than 10% moisture, they may become too fragile to be transported.
The decortication process generally involves three steps:
Scutching: Passing the stalks through a series of rollers to separate the hemp fibres. During this step, the woody core is pushed and separated from the soft fibres. This is another step where good drying comes into play. The soft spot between 10% and 15% moisture is the key here. If the stems are too dry, they will be reduced to powder. If they are too wet, they will not break and will not separate properly.
Hackling: Comb the short and intermediate fibres out of the stem.
Twisting: Individual twisting of the yarn fibres.
Modern decortication techniques use a steam explosion (treatment of fibres with steam through a pressurized chamber) and ultrasonic decomposition (decomposition of fibres using ultrasonic waves) to maintain the integrity of the fibres throughout the process. These techniques are not as severe on the stems and allow processors to use the fibres on cotton and wool processing machines.
Baling and storage
The hemp stalk is packed for transport and long-term storage using traditional baling presses. Large round balers are more suitable for hemp, as they allow deeper drying, as they do not wrap hemp as tightly as square balers. Hemp should be stored in a dry environment under conditions that minimise absorbable moisture. It is also important to check for wet stains when baling to further prevent mould.
How is hemp grown differently from marijuana?
Male hemp plants flower much faster than females and do not produce as much fibre. Unlike marijuana fields, most female hemp fields have sporadically placed males. The male hemp plants release pollen for the female hemp plant to produce seeds that will either be used for future crops or sold as food. In marijuana fields, males are usually eliminated to ensure maximum production of sensimilla flowers.
Although marijuana cultivation requires significant spacing to reduce the risk of mould or bacteria, hemp can be planted more densely. Most marijuana crops are planted at one (1) plant per four (4) square feet. Hemp plants that are grown for hemp oil are planted at approximately 40 to 60 plants per four (4) square feet. Hemp plants that are grown for fibre are planted even more densely at a rate of approximately 100 to 120 plants per four (4) square feet.
Hemp plants are almost always grown outdoors, unlike marijuana plants, which are mainly planted in greenhouses or indoors. Because hemp is susceptible to the same predators as the diseases and insects that attack marijuana, the hemp industry uses a technique called crop rotation, which involves planting alternate crops in the same location to prevent the accumulation of these organisms and to allow nutrients to return to the soil. The specific order of crop rotation and the types of crops rotated with hemp will depend on the location of the farm. Hemp is also used as a rotational crop on farms where it is not the primary agricultural product.
Is hemp growing legal in the United States?
The Agriculture Act of 2014, better known as the Farm Bill of 2014, signed by Democratic President Barack Obama, includes Section 7606, which allows universities and state agriculture departments to grow industrial hemp, provided it is grown and used for research purposes. Under the Agriculture Act of 2014, state departments and universities must also be registered with their states and rely on state laws and regulations for permission to grow hemp.
As part of the Agricultural Improvement Act of 2018, or the Agricultural Act of 2018, signed by Republican President Donald Trump, the Hemp Agriculture Act of 2018 eliminated hemp (less than 0.3% THC) from Schedule I, the most restrictive classification of controlled substances considered highly susceptible to abuse and without medical benefit. This movement has allowed the cultivation and distribution of hemp as a legal agricultural product. Under the Hemp Cultivation Act, the cultivation of hemp is no longer limited to State departments and universities. In addition, the law provides hemp growers with rights to water, crop insurance and federal agricultural subsidies, as well as legal access to national banking services. Hemp can also be transported across state borders.
Prior to the Hemp Agriculture Act of 2018, 41 states had enacted legislation on industrial hemp. Thirty-nine of those states had legalized national hemp cultivation programmes that defined hemp specifically to differentiate it from marijuana, establish licensing requirements and regulate production. The Hemp Farming Act now requires government departments of agriculture to consult with their governors and key law enforcement officials on a program to regulate hemp, which will then be submitted to the U.S. Secretary of Agriculture for approval. Under section 297B of the bill, hemp regulatory programs must include a system for maintaining information on all land on which hemp is grown, procedures for testing THC levels in hemp, and procedures for disposing of products that violate THC content restrictions.
World history of hemp
Hemp has been cultivated worldwide for thousands of years. The oldest documented evidence of hemp cultivation is a hemp rope dating back to 26,900 BC, found in the Czech Republic.
Some of the earliest known prolific uses of hemp began in China around 10,000 B.C., where hemp was used in the manufacture of clothing, rope and paper. The Yangshao people, who lived in China from about 5000 BC, wove hemp and pressed it into their pottery for decorative purposes. Between 5000 and 300 BC, hemp was also cultivated in Japan and used to make fibre and paper.
Cannabis played an important role in Greco-Roman cultures as a source of fibre, an intoxicant and a medicine. Cannabis seeds were discovered in the ruins of Pompeii and the Greek rhetorician Athenaeus noted that hemp was used to make ropes between 170 and 230 B.C. The Roman author and naturalist Pliny the Elder also referred to a decoction of cannabis root as a treatment for joint stiffness and gout in the first (1st) century B.C.E.
The question of when and how hemp originated in the New World is still very controversial. Although Christopher Columbus long introduced it to the Americas, hemp was discovered in Native American civilizations prior to Columbus' arrival. The report "Prehistoric Textile Art of the Eastern United States" by William Henry Holmes, published in 1896, indicates that hemp originated from American Indian tribes of the Great Lakes and Mississippi Valley. Hemp products from pre-Columbian native civilizations have also been found in Virginia. The Vikings, who used hemp to make ropes and sails, may also have brought hemp seeds with them when they attempted to colonize the New World.
Jamestown settlers introduced hemp to colonial America in the early 1600s for the manufacture of rope, paper and other fibre products and even fined those who did not produce hemp. U.S. presidents George Washington and Thomas Jefferson grew hemp.
Hemp was an important crop in the United States until 1937 when the Marihuana Tax Act virtually wiped out the American hemp industry. During the Second World War, hemp experienced a resurgence in the United States as it was widely used to make military items ranging from uniforms to canvas and rope. The U.S. Department of Agriculture even published a short documentary entitled "Hemp for Victory" in 1942, in which it argued that hemp was a useful crop for war.
However, the revival of hemp in World War II was short-lived. Until the passage of the Farm Bill in 2014, the 1970 Controlled Substances Act kept industrial hemp production dormant. Today, hemp is rapidly becoming an indispensable resource for CBD oil and other CBD-based products.
Cannabis Cultivation: Introduction to Marijuana Cultivation
Arguably, our relationship with cannabis begins and ends with cultivation. All forms of cannabis that we consume come from a cultivated plant. The value of the cannabis plant, medicinal or otherwise, depends largely on what we do with it-how and when we grow it, how we refine it for our own consumption, and even the words we use to describe it.
Local laws and regulations on cannabis cultivation
In most countries and local jurisdictions where cannabis is legal - whether for medical or recreational purposes - some form of domestic cultivation is generally permitted, but laws on cultivation vary considerably from country to country and even from city to city. If you are a potential and current producer, you should be aware of the laws and regulations in your jurisdiction before you start growing cannabis.
Cannabis Plant Sex and Anatomy
Male and female cannabis plants share a common basic anatomy: roots, stems and leaves. Both sexes of the plant produce trichomes, the glandular appendages on the flower surface that produce and maintain the plant's cannabinoids and terpenes. However, the female plant produces many more trichomes than the male plant. Beyond these bases, the anatomy of cannabis varies significantly between male and female plants.
In our shared history with cannabis, authors, scientists, growers and industry specialists have used competing terms to describe the same reproductive plant anatomy. Due to a long period of prohibition, botanical terms have often been misused or entirely replaced. In addition, popular colloquial terms have become interchangeable even though they have different meanings.
So let's clear up some of the confusion and map the anatomy of both sexes by first identifying botanical terms and then clarifying some of the common colloquialisms we have inherited.
Anatomy of the female plant
The female cannabis plant is a pistil, which means it has pistils and stigmas. You may have heard of female cannabis plants called "sinsemilla", which has been translated into Spanish as "seedless". Sensemilla refers to all female plants that are unpollinated. Sensemilla plants are ideal for marijuana growers as they offer the best potential for cannabinoid yield. Pollinated female flowers, or female flowers with seeds, produce a less smokable product than seedless marijuana flowers.
The reproductive anatomy of the female plant includes:
Colas: The flowers produced by the female plant. Colas are covered with trichomes rich in cannabinoids and terpenes and are commonly called buds or buds. A cannabis bud should not be confused with the botanical definition of the word bud: an emergent plant.
Bract: A small ladder-like leaf structure that encapsulates and protects the seed. Bracts are often called calyxes, although this term is botanically incorrect. The female cannabis plant, however, has calyx cells in the delicate layer of tissue between the seed and the bracts that encapsulate it.
Stigmata: The reproductive parts of the cannabis plant, which collects pollen from the male plant. Stigmas are commonly and erroneously called pistils.
Pistil: The reproductive parts of the female cannabis flower that are activated if pollen is captured by the stigmas.
Sugar leaves: The small leaves that hold the cannabis buds together. They are called sugar leaves because of the high concentration of trichomes that look similar to sugar.
Anatomy of the male plant
The male cannabis plant is a staminate, which means that it has reproductive organs that produce stamens or pollen. Male plants are grown for fibre and for breeding new varieties. During their flowering phase, male cannabis plants release pollen, which will induce a female plant to start producing seeds. This practice diverts energy from flower production and reduces overall yield. To maximize the yield of your flowers and prevent seed production, keep male and female plants as far apart as possible.
The male cannabis plant is capable of producing cannabinoids, but its trichomes are scattered on the surface. Males do not produce as many trichomes as females.
The reproductive anatomy of the male plant includes:
Etamine: An organ of the male plant that produces pollen and releases it into the wind, where it can be transported to the stigma of a female plant for pollination.
Anther: The bags that produce and hold pollen in the stamen. The anthers hold only a small filament. Together the anther and the filament form a stamen.
Pollen: microscopic grains produced and contained in the anther that fertilize the female plant when they are released.
A hermaphrodite is a rare monecious plant, which means that it develops male and female sexual organs. The term monecious comes from the root "mono" which means "one". Although a plant can show both signs, hermaphrodites form mainly if a female plant is exposed to extreme conditions during its main growth phases, such as insufficient light or harsh environmental conditions. The signs of a hermaphrodite usually show up late in flowering.
In a final attempt to continue their seed line, a sensemilla crop will sometimes produce a few hermaphrodites. Although the pollen of these hermaphrodites is often non-viable, marijuana growers should eliminate hermaphrodites when they occur to eliminate the risk of pollination. Hermaphrodites will also produce a lower total floral yield because the plant is forced to expend energy to produce seeds that would otherwise be used to produce trichome-rich flowers.
The three main growing environments for cannabis
Growing cannabis outdoors exposes crops to the elements, providing natural light and significantly reducing costs for growers. In the absence of artificial lights or required fans, electricity can only be required for irrigation.
While exposure to a natural environment is generally beneficial to plants, exposure to harsh environmental conditions can be a barrier to growing crops outdoors. Rain, insects, invasive plants such as thistle, animals and extreme weather conditions are all potentially lethal factors for crops. Outdoor cultivation also limits growers' control over the environmental crossover of neighbouring fields. In short, your fellow farmer's pesticides could become your pesticides if they are not expertly applied.
Outdoor cannabis cultivation relies on the sunlight available throughout the seasons, during which the plant is exposed to the full spectrum of light available in nature at that time of year. Outdoor growers have a longer growing cycle and usually harvest only once a year.
Growing cannabis in a greenhouse offers the free sunlight of outdoor cultivation, but with much tighter environmental control. Greenhouses allow growers to control natural light with a blackout shade or similar roofing system. Greenhouses also offer the option of adding electric lighting to supplement sunlight on cloudy days with an extra layer of protection against animals, pests and extreme environmental changes.
One of the disadvantages of greenhouse growing is the initial cost required to have such a structure. Greenhouses range from temporary plastic and PVC structures to permanent structures that allow growers to control all environmental aspects and use advanced growing methods, including light deprivation.
Another risk in greenhouses is that pests can spread more quickly in the enclosed environment. Protection against environmental cross-breeding is also limited depending on the type of greenhouse structure.
Indoor growing is usually carried out in a warehouse, which requires artificial lighting and the use of air conditioning and dehumidification systems. The intention of indoor growing is to reproduce the elements of nature that facilitate plant growth while maintaining total control over all environmental parameters. The major disadvantage of indoor growing is the high initial and recurring costs associated with building structure, equipment, water, electricity and other utilities.
Techniques for the propagation of cannabis
Propagation covers the entire growth cycle from seed to harvest. Cannabis can be grown from seed or from a cutting of another plant.
Cannabis seeds, formed when the pollen fertilizes the female plant, are ready to be planted and grow as soon as they have successfully germinated or when the root has split in the seed. Although you can plant your seeds directly into the ground, it is recommended that you germinate them in a damp paper towel before planting. Home growers often start with feminized seeds to ensure that the adult plant is a flowering female.
Seed propagation is commonly referred to as sexual propagation and is often a preferred method for growing cannabis outdoors, as it provides a more durable plant. Not only do sexually reproduced crops have a higher yield potential than clones, but they are also more resistant to pests, diseases and illness.
This is the most commonly cited disadvantage of growing plants from seed. Plants propagated from seed do not retain the exact phenotype and observable physical and chemical characteristics of the mother plant. This causes variations and inconsistencies in cannabinoids and terpenes that producers and consumers generally find undesirable.
Although most growers want uniform plants, they sometimes grow a large number of plants from seed in order to be able to select plants that produce unique physical and aromatic characteristics. This practice is commonly referred to as pheno hunting and is practiced by most nurseries.
Asexual multiplication, also known as cloning, is the replication of a single mother plant outside the sexual means of reproduction. Cannabis clones usually begin by cutting a stable mother plant that can produce a genetically similar plant under the right growing conditions. The central objective of a clone is to reproduce and preserve the genetic identity of a cannabis plant. When grown under the same environmental conditions as the mother plant, a clone is infinitely more likely than a plant grown from seed to exhibit the physical characteristics of the mother plant, as well as its cannabinoid and terpene profile. This should also reflect the mother's ability to absorb nutrients and resist pests or fungi.
Because they are not exposed to the genetics of many plants (but receive the same genetic code as the mother plant), clones have a much better chance of preserving the desired characteristics of a mother plant. Plants grown from clones also allow growers to determine the environmental conditions under which to maintain these ideal genes, as well as to determine optimal feeding schedules, flowering times and nutrient recipes.
Lack of genetic diversity is good for growers, but it can also have catastrophic consequences. If plants are exposed to adverse environmental conditions for which they have no genetic defence, an entire crop can be destroyed.
Selecting a cannabis growing medium
Whether a plant is grown from a clone or a seed, both need support as a basis for a healthy life. A growing medium is the material in which plants are fixed during the growth cycle. Whether you use hydroponics, aeroponics or traditional soil cultivation, the growing medium you choose must provide the plant roots with air, water and nutrients.
Soil is the most commonly used medium for cannabis cultivation. Healthy soil is an exceptionally stable growing medium, allowing sufficient moisture retention that gives the grower sufficient time between waterings. Soil is readily available and relatively easy to work with, making it an effective growing medium for as many growers as possible - from potential home-growers to bona fide experts. The soil can be used for both indoor and outdoor cultivation.
Hydroponics is the preferred medium for indoor growers who feed the plants with a nutrient-rich liquid solution. Perlite, vermiculite, coconut and hydroton beads are all commonly used hydroponic carriers that allow for optimal nutrient absorption and reduced water consumption compared to soil. Hydroponic methods are also frequently used in greenhouses, but rarely for outdoor cultivation.
The major disadvantage of hydroponics is the rigorous attention to detail that is paid in practice. Hydroponic media are much more sensitive to temperature extremes. Too much heat, in particular, can be very damaging as it invites bacteria and disease. Meanwhile, the pH of the water and nutrient levels must be constantly monitored so that the plant gets what it needs to grow strong.
Aeroponic systems work in the same way as hydroponic systems, but instead of keeping plant roots submerged in water, an aeroponic system suspends them in an environment of fog and air where they absorb water, nutrients and oxygen. An aeroponic system may have the potential for maximum yield, but it is also much more modest than other systems. Environmental and growth control factors require careful and constant attention for an aeroponic system to be effective.
Germinating seeds or rooting of cannabis clones
The germination phase takes place from the time the embryo of a seed is exposed to water until the seed has germinated from its feather, or initial taproot. Germination only occurs when plants are grown from seed and generally takes between 12 hours and three weeks, depending on the vitality of the seed, its age and the germination techniques chosen by the grower.
The simplest way to germinate a cannabis seed is to place it about 3 millimetres deep in moist soil. Germination soils are also an option, designed with mixtures of micronutrients that facilitate healthy germination. Many growers prefer germination with a towel, in which the seeds are placed between two damp paper towels and then immediately transferred to a growing medium once the taproot is exposed.
Removing the fan leaves from the plant can be considered a training technique to channel the plant's energy into the production of larger colas by limiting the amount of foliage required by the plant and increasing the amount of direct light directed to the growing sites below the canopy. This also helps to reduce the risk of pest or mould infestation. However, the fan-shaped leaves absorb light and provide energy to the plant. Growers should therefore be careful when removing them.
The flowering stage of cannabis
The flowering phase takes place when the female plant produces colas covered with trichomes and when the male plant produces and releases its pollen. Cannabis plants flower naturally during the 12/12 photoperiod, when the plant receives 12 hours of light and 12 hours of darkness. In nature, the light hours are optimal for the flowering of the cannabis plant from July to November in the northern hemisphere. At the autumn equinox in September, the sun is in the sky for 12 hours a day, and daylight slowly diminishes until winter. The opposite is true in the southern hemisphere.
Indoors or in a controlled light greenhouse, the introduction of a 12/12 cycle of artificial light will force a cannabis plant to flower.
When is cannabis ready for harvest?
A female plant is usually ready for harvest when the glands at the top of the hair-stalk trichomes turn from clear to milky white. Some growers may also use the colour of the pistils to time their harvest. Pistils tend to change from white to orange or red to brown. Growers should also be aware of the typical flowering times of the cultivars they grow.
Harvest your cannabis
Once the cannabis plant is ready to be harvested, its precious and delicate trichomes are in one of their most vulnerable states. Overexposure to oxygen, light and heat can degrade cannabinoids and terpenes or activate them prematurely. Trichomes become more fragile and therefore more likely to become detached from the plant if mishandled under extreme conditions. When harvesting cannabis plants, growers should implement drying, pruning and drying methods that reduce agitation of the plant to limit damage to the trichome glands.
When your cannabis is ready to be harvested, cut the whole plant at the base or cut it into large branches. Hang the plant or cuttings upside down on a clothesline in an environment that is neither too dry nor too wet. At this stage, some growers begin to manicure their plants by cutting off all the fan leaves and some sugar leaves. Plants should be left hanging upside down until the stems break slightly when bent.
Avoid losing trichomes by keeping your branches from touching a surface while drying. Contact with the surface can damage the trichomes and cause them to detach from the plant. Depending on environmental conditions, the initial drying process usually takes three to seven days.
The trichome gland will undergo some changes during the drying process. The most noticeable is the loss of the extremely pungent odour. This is due to the loss of the more temperature sensitive terpenes, or hydrocarbon compounds that produce the unique aroma of each cultivar. Studies have shown that more than 30% of monoterpenes, or terpenes with two isoprene units - as opposed to the three isoprene units of sesquiterpenes, four isoprene units of diterpenes, etc. - have been lost. - produced during the flowering phase are lost during the drying process. In addition, when cannabis is dried, the terpene compounds are oxidized and the terpene technically becomes a terpenoid.
Once the initial drying is complete, it's time to finish cutting and manicuring your bud. Cannabis is usually cut to remove excess sugar leaves which, although consumable, have a lower concentration of trichomes than the flower and can be hard when smoked.
Start cutting by holding your cola by one stem and gently cutting the leaves and sugar stems that surround the buds. This is a very delicate process that requires attention to detail. Ideally, this is done on a screen to collect any trichomes that may detach from the plant. Be very careful when handling your bud. Every moment of contact can lead to the loss or damage of trichomes. Whenever possible, hold your plants and branches by the end of the stem.
Wet vs. dry trim
While most growers cut their cannabis after drying, some prefer to cut while the plant is still wet. When cannabis is cut just after harvest, the leaves are still full of chlorophyll, which can lead to a lingering grass-like aroma. The more traditional approach is to cut the plant once it has lost most of its moisture.
Polymerization can be considered the final drying step, allowing the bacteria on the bud surface to break down any residual chlorophyll and ensuring that the colas are neither too wet nor too dry.
This should be a gradual process, as buds that are too dry will degrade more easily during transport and packaging, lose potency and become unnecessarily hard to smoke. On the other hand, a bud that is too moist can develop mould. Preserving fragrance and flavour is a major concern for cannabis growers while healing. Overexposure to light, oxygen and high temperatures can degrade cannabinoids and terpenes and eventually reduce potency. Finding a delicate balance between dry and moist is the key indicator of a finely dried bud.
Growers should never rush to cure. The process often requires a lot of trial and error. One to two months is usually sufficient time for curing, although the preference and time available for curing may differ among growers. It is important to keep the environment around your plants cool during the drying phase.
This curing process can be accomplished by placing your buds in a glass jar or Rubbermaid purse for 4-8 weeks. During the first week or two, the containers should be opened daily to allow fresh oxygen to replace the air in the container. This process is called burping and is repeated until the heads have the optimum moisture content. During the last two weeks of processing, the containers are opened every 2-3 days.
Cannabis storage tips
Glass jars are the ideal option for short-term storage. Ideally, cannabis jars should be opaque and airtight for sufficient storage of cannabinoids and terpenes. For long-term storage, growers should vacuum-seal their final product whenever possible.
Cannabis cultivation is a dedicated practice for home and professional growers. Mastering marijuana cultivation requires a lot of patience, trial and error, but with time - and a few good suggestions from experienced growers - you'll be able to give your plants a healthy life from seed to harvest.
Why does cannabis need to be tested?
Cannabis has many medicinal benefits, and as all medicines contain information on their concentration and dosage, cannabis products are now subject to the same standards. International organizations are developing regulations and standards on acceptable limits for certain compounds to ensure that cannabis products do not compromise a person's immune system. The two main reasons why cannabis products are tested are: to ensure that the products are safe for human consumption and to give consumers an idea of the potency of the product they are using.
Cannabis plants act like a sponge during cultivation and absorb everything they are exposed to, from nutrients and heavy metals from the soil to pesticides that may have ended up in a greenhouse from the neighbouring farm. For this reason, cannabis products are now tested for all materials that may remain in the final flower. Regulators have begun to set maximum acceptable quantity limits for residual solvents, pesticides, heavy metals, microbes and mycotoxins.
The use of hazardous pesticides, fungicides and growth regulators on cannabis has been documented. These residual toxins create potentially dangerous safety issues for patients when consumed. Molds and fungal contaminants should be of concern to anyone who uses cannabis for medical purposes, particularly those who are prone to asthma, allergies, or have weakened immune systems.
Similar to tomatoes at the grocery store or a shirt you buy online, there are acceptable limits that agencies have set for each compound and they are all listed in a cannabis product "certificate of analysis". A certificate of analysis shows the results of laboratory tests and allows consumers to ensure that the products they consume are free of unwanted chemicals, parasites or organisms that can compromise a person's immune system, including residual solvents, microbiological contaminants, mycotoxins, heavy metals and pesticides.
Laboratory tests are the only way to know the cannabinoid and terpene makeup profile of the cannabis product you are using. These two variables are the most important ones to consider when selecting your cannabis because they directly influence the experience you will have.
Because cannabis is so much influenced by the environment in which it is grown, a cultivar grown in one part of the world may look similar to another cultivar you have known in the past, but it may contain completely different amounts of cannabinoids and terpenes, which will change your experience. Simply put, one grower's "Blue Dream" may have a different potency and chemical composition than another. It is important to pay attention to the amount of cannabinoids and terpenes present in cannabis before you consume it in order to better anticipate the effects you may experience.
Indoor cultivation is mainly used for control, reproducibility and risk mitigation. The goal is to artificially create the perfect environment for your plants at all stages of their growth. This is achieved through precise control of lighting, temperature, humidity, carbon dioxide content and air movement within each indoor grow room - making indoor growing a viable option that is not unique to cannabis.
Indoor cannabis cultivation began in the 1970s, during the era of prohibition. As law enforcement cracked down on the illegal outdoor cultivation of cannabis, growers responded by moving many of their operations indoors - not only allowing growers to hide their valuable plants from prying eyes, but also freeing them from the limitations and challenges imposed by location.
Recurring equipment and utility costs are higher than for outdoor facilities and greenhouses. However, specialized indoor growing equipment allows growers to have multiple crops per year and a more reproducible product. For those who are detail and technology conscious, indoor gardening can be fun and rewarding.
To set up an indoor garden, you will need equipment to create a stable environment that mimics the outdoors. This includes special lighting, fans to recreate wind, dehumidifiers to maintain adequate humidity, and all the basic supplies a plant needs to survive from the water to grow media and nutrients.
Planning, designing and implementing an indoor garden can be daunting, but understanding the basics can help a new indoor grower get on the right path to healthy and successful growth.
Growing Your Crop: Means and Methods of Feeding
The first step in creating an appropriate indoor growing environment is to identify the medium and irrigation method you will use to provide your plants with the appropriate nutrients throughout the growing cycle. Think of a home-like environment for your plants' roots and the irrigation method you have chosen as the vehicle by which you feed your plants with nutrients.
Unlike growing outdoors - where you almost always use soil to grow your plants - growing indoors offers many different options for growing systems and media. Some media are easy to work with, while others offer more control over the finer details. Different media retain moisture at different rates, which determines how often plants need to be watered. Some media harbour beneficial microbes that can help plants eat nutrients. Others create environments that, although less stable, allow for better control of a plant's metabolism.
The two main growing media options for an indoor garden are soil and hydroponic media. The level of expertise is the main factor to consider when choosing between the two.
The floor is an excellent choice for beginners. It can be much more forgiving and requires less precision when watering and feeding the plants need extra nutrients. Less frequent watering and a stable pH foundation can greatly increase the likelihood of a successful first harvest. Soil also contains beneficial microbes and nutrients that help keep plants healthy, although it can also create conditions for the spread of pests. Working with soil and hand-watered plants can be messy, but it will help you become familiar with the rate at which your plant consumes water and nutrients.
Hydroponic media is a viable alternative to indoor soil, but it is considered an advanced media because it brings with it a set of challenges that can be difficult for beginners.
Hydroponics is a general term for growing plants in a nutrient solution with or without an inert medium to provide mechanical support. Mediums such as coco coir, rockwool and hydroton can greatly increase the control a grower maintains over the growth of a plant. When a plant's root system is exposed, hydroponically grown cannabis can grow faster and more efficiently, requiring less water and nutrients, but also extensive monitoring systems to ensure that a stable pH is maintained.
Advanced soil-less media
Coconut coconut, or coconut fibre, is the fibrous material found inside the coconut shells. As a by-product of the coconut industry, it is promoted by producers as a sustainable and renewable medium. Coconut coir is an inert, pH-neutral medium that does not provide or maintain any nutrients. These qualities are excellent for experienced growers, as they allow growers to rapidly change the pH and nutrients to which a plant is exposed. Coco coir can be used alone or added to the soil to improve drainage capacity and allow for better aeration.
Whether you grow two (2) or 30 plants in your home, growing equipment requires a significant amount of electricity, mainly lighting and air conditioning. Make sure that all electrical equipment is installed by a qualified professional to reduce the risk of an electrical fire. You don't necessarily need to be an electrician to design an indoor grow operation, but it is essential to have a basic understanding of the relationship between watts, volts and amps. The equation below can be used to determine if your property has the minimum power requirements for an indoor garden:
Amps = Watts/Volts
Always make a list of electrical requirements for each piece of equipment and make sure your electrical panels can handle the electrical load before purchasing large equipment.
Water quality is another key aspect of indoor gardening. It is important to determine water acidity and overall mineral content before planting. The pH, acidity or alkalinity of the water can easily be checked using a portable water quality indicator. The same device can be used to check the total mineral or chemical content of your water. Knowing these contents will help you determine the correct amount of nutrients to feed your plants.
Most local jurisdictions require you to mitigate the smell of your plants so as not to disturb your neighbours. Activated carbon filters absorb plant odours in your grow tent. Adding a charcoal filter to your heating, ventilation and air conditioning (HVAC) system or installing a filter in your grow tent is a great way to significantly reduce odour. The size of the filter depends largely on the size of your room. Make sure it is properly sized and installed and keep track of the life of the filter as its efficiency decreases over time.
Even when you are growing cannabis legally, it is still a good idea to minimize your public visibility as a grower and take some mild to moderate precautions. Simple things like not labelling your location when you post grow photos or hiding the glare from your grow lights when you use them at night can go a long way to keeping your precious indoor garden safe.
Creating the Perfect Environment: Lighting
Choosing the right horticultural lighting for your indoor cultivation can make the difference between success and failure. Correct lighting is important because it promotes photosynthesis. In other words, your plants will not grow without good lighting. Light also controls the photoperiod, the period during which a plant is exposed to light. During the vegetative growth phase, plants need a minimum of 16 hours of light. The most common schedule during this phase is 18 hours of light and 6 hours of darkness. To start flowering, the plants need a shorter day with 12 hours of light and 12 hours of darkness.
The intensity of the light and the location in your grow room are important aspects to consider when choosing a light. Low light levels will slow photosynthesis, delay growth and result in poor yields. If your light is too far away, the plant will not receive enough. If your light is too close, it can damage the plant and ruin your buds.
There are several different types of culture lamps that serve different purposes, each with their own advantages and disadvantages.
Fluorescent lamps are affordable lamps that use minimal power to produce low-intensity light. They are available in strips or larger arrays of multiple bulbs, and are most often used during germination and propagation of seeds and clones. They should not be used during the flowering phase.
Metal halide (MH) lamps are a type of high intensity discharge (HID) lamp that works by igniting a gas in a tube with a spark of electricity. Metal halide bulbs emit a spectrum of light that is beneficial during the vegetative phase. They emit more usable light for a plant than a fluorescent bulb, but tend to cost much more.
High Pressure Sodium (HPS) bulbs are highly efficient HID lamps that produce the perfect spectrum to promote growth during the flowering phase. Most HPS bulbs are double-ended and can last up to 10,000 hours without loss of efficiency. Although these lights are the workhorses of most grow rooms today, they produce a significant amount of heat that must be removed, increasing the need for air conditioning (AC).
Light-emitting diode (LED) lights are another form of high-intensity lighting that is gaining popularity. LED lights produce a spectrum suitable for all phases of a plant's life. They generally cost more than other grow lights, but they last longer, are more efficient and produce less heat than other HID lamps.
Creating the ideal environment
When it comes to growing cannabis indoors, you need to make sure you provide your plant with the optimal temperature, humidity, air circulation, CO2 and nutrients.
Temperature and Humidity
Maintaining the ideal temperature and humidity at all times is crucial for the health of your plant. Some plant varieties prefer warm, humid climates, while others like it cool and dry. Keeping them alive and healthy means controlling the temperature and humidity when the lights are on or off.
Air conditioning and humidification systems are used to control the temperature and relative humidity of an indoor grow room. The size of each unit is based on the amount of heat produced by the lights and other equipment. In an open grow room, suction and exhaust fans are used to constantly exchange air within the room to maintain a constant temperature. In airtight rooms, mini AC systems are used because they circulate air through the room without bringing in fresh air.
Although AC systems maintain temperature, they also dehumidify rooms. Fluctuations in humidity can be detrimental to plant health and should be controlled with a dehumidifier or humidifier, depending on the conditions.
Advanced growers use digital environmental controls to monitor all equipment responsible for maintaining a stable environment (i.e. fans, air conditioning, dehumidifier, sensors, temperature, humidity, etc.). These environmental controllers can be well worth the price for the peace of mind they provide.
With lighting and air conditioning in place to control the environment, indoor cannabis plants will require large amounts of fertilizer or nutrients. Hydroponic systems lack the basic nutrients found in the soil, leaving growers to feed their plants with nutrient concentrations - the exact formula depends on the variety and the stage of cultivation of the plant. In hydroponics, salt-based nutrients are usually in the form of a concentrated liquid or dry soluble powder that can be mixed with water. As a cannabis plant grows, its nutrient requirements change. For this reason, different lines of nutrients are available for different phases of growth. Most nutrient lines come with recommended feeding tables.
Carbon dioxide supplementation
Controlling the amount of carbon dioxide (CO2) available in your garden is another aspect of indoor growing. During photosynthesis, CO2 is converted into sugar, which the plant uses as energy to grow its vegetation and, ultimately, its seeds or flowers. Adding CO2 to your indoor garden can greatly improve your yields. While the atmosphere naturally has an average CO2 concentration of about 400 parts per million (ppm), most indoor growers try to maintain a range of 800 to 2,000 ppm, depending on the stage of plant growth. Levels above 2,000 ppm can damage plants, and anything above 3,000 ppm can be harmful to humans.
The amount of CO2 you add to your garden depends on the amount of light your plants receive, their growth stage and their overall size. CO2 should only be used during the daytime period because plants cannot use CO2 at night or in the dark. Sealed grow rooms are ideal for supplementing CO2, as open rooms tend to release CO2 faster than the plants can use it.
CO2 can be added to an indoor garden using compressed gas tanks or generators. Using compressed CO2 tanks is the most common method because they are readily available, easy to install and do not add extra heat to your room like a CO2 generator does.
Air movement is the least expensive element to create an ideal environment for your plants. Even a gentle breeze can help prevent pests and microbes from landing on your plants, move oxygen and carbon dioxide around the leaves and create a uniform environment in your room. One of the easiest ways to maintain adequate air circulation is to hang oscillating fans on the walls and place a small box fan on the floor. The purpose of air circulation should be to mimic a light breeze and avoid strong gusts that could harm your plants.
Tips for success
The health of your garden depends entirely on the environment you create and the equipment you choose. It's easy to buy a new line of nutrients, but much harder to replace an undersized air conditioner. Careful planning before you grow will prevent many costly mistakes.
The cleanliness of an indoor garden cannot be overestimated. Walls, floors, trays, irrigation lines, tanks, lights and fans should be cleaned with a 3-5% solution of hydrogen peroxide, an effective sterilizing agent that leaves no dangerous or toxic residue behind. Be careful what you bring into your grow room. Pets, dirty clothes and contaminated clones can introduce unwanted pests and diseases.
Keeping a crop journal and recording all the major aspects of your crop is one of the easiest and cheapest things you can do to become a better grower. Recording daily temperatures, water and feed amounts will help you identify problems and can give you something to show to other producers who can help you solve problems, increase your yields and save a little money.
Outdoor growers use the best nature has to offer in the hope of producing the best possible crop. Cannabis has been grown outdoors for thousands of years. But before putting a seedling in the ground, it is best to know how the process works and under what conditions outdoor growth is most successful.
Growing outdoors is an excellent option for those new to cannabis cultivation or for those looking for a more natural environment for their plants. Outdoor gardens are cost effective as they do not require costly environmental controls and require few resources to get started.
When growing outdoors, cannabis is exposed to the full spectrum of sunlight. Each part of the light spectrum contributes to the growth and development of the molecules that make up the resulting plant, including terpenes and cannabinoids. Outdoor growers choose this method of cultivation to maximize exposure to natural light.
However, outdoor growers must control natural elements that can potentially reduce overall yield or quality. Among the many factors outdoor growers must consider are reduced light on cloudy or rainy days, the possibility of being invaded by a wide variety of pests, and limiting the growing season to one per year.
To grow cannabis outdoors, the bare minimum is to have basic gardening tools, soil, pots, a garden hose with access to water and a place in your backyard that receives lots of sunlight.
Using Mother Nature to grow cannabis
Cannabis is a hardy plant that has adapted to climates around the world. From the cool, arid mountains of Afghanistan to the humid regions of Colombia, the plant has had to adapt over time to build its defences against a host of conditions. But cannabis is always sensitive to extreme weather conditions. From strong winds breaking branches to excessive rain causing mould, the outdoors presents challenges to growers that can be avoided with sufficient planning.
Becoming intimately familiar with the local climate and seasons is one of the most important steps in producing high quality outdoor marijuana. Before growing, you need to know the ideal temperature your plant needs to grow, the photoperiod of the season or the amount and intensity of light available throughout the growing season, the best site and the optimal time for planting and harvesting.
Some cannabis genetics have adapted to specific climates and are able to grow more easily under some conditions than others, so growers pay special attention to the cultivars, more commonly known as strains, that they choose. A little research will ensure a successful harvest. Although cultivars can vary, there are a few general rules that will help you no matter which cultivar you choose.
Daytime temperatures between 75 and 85 degrees Fahrenheit, or 23.9 to 25.4 degrees Celsius, are ideal for cannabis, while temperatures above 88 degrees Fahrenheit (31.1 degrees Celsius) or below 60 degrees Fahrenheit (15.6 degrees Celsius) can retard its growth. Cannabis is considered heat-tolerant, but sustained increases and extreme decreases will usually lead to complications that could eventually kill your plants.
In the Northern Hemisphere, cannabis can be planted from early to mid-spring and usually harvested in mid-fall depending on the cultivar. In the Southern Hemisphere, the growing season will be reversed, with planting in early to mid-fall and harvesting in mid-spring.
During the first half of the season, the diurnal period increases until the summer solstice, which occurs in the Northern Hemisphere on or about June 21 and in the Southern Hemisphere on or about December 21. As the hours of daylight increase, the vegetative stage of the plant takes place. During the vegetative stage, the plant will develop roots and stems that will serve as a base for growth until flowering.
After the solstice, the available hours of daylight decrease, allowing the plant to naturally move into the flowering period. Cannabis is a short daytime plant, which means that it will start to flower as the nights get longer and the hours of sunlight decrease.
Most cultivars will start flowering as soon as they receive less than 15 hours of sunshine per day. The latitude of your garden has a direct impact on the number of hours per day your plants receive light.
It is important to plan your planting schedule to ensure that your plants are able to complete their flowering period before the cold, wet fall weather can affect your plants.
Choosing the best site for growing cannabis outdoors
Choosing the best location for your garden is another important factor that can affect the yield and quality of your plants. Growers in the northern hemisphere should try to place their plants in a south-facing area to ensure that they receive maximum sunlight by facing the arch of the sun near the equator. The opposite
The reverse is true for the southern hemisphere.
Whenever possible, use the structures and natural formations in your garden as windbreaks to avoid excessive stress on your plants that could lead to branch breakage.
If you live in a climate with exceptionally hot, sunny days, you can use shade cloth to prevent your plants from overheating. In cold areas, natural enclosures and cement or brick walls can be used to help retain all the heat available to keep your plants warm.
Depending on where you are, you may need to plan for rain. In most areas, the rainy season is usually aligned with the end of the flowering and beginning of the harvest period, but this is not always the case. Rain can interfere with the flowering of an outdoor crop and being prepared to cover or move plants can help ensure a successful harvest. If it rains on your plants, be sure to shake off the excess water immediately as excessive moisture can lead to mould growth that will ruin your crop.
Planning your garden
Seeds versus clones
Deciding to start with seeds or clones will change when and how your plants are introduced outdoors.
Plants grown from seed are generally stronger and more vigorous than clones because they produce a strong taproot that clones are not able to produce. The vigour that comes from deep roots can be an advantage when dealing with difficult environmental conditions and pest pressures. Disadvantages of seed cultivation are the extra attention required for germination of seedlings, the need to eliminate males before they pollinate females, and the wide variability in growth characteristics that results from their genes.
If you decide to use seeds, be sure to start them about a month before starting the clones to give them time to germinate and develop their taproots properly.
There are also many advantages and disadvantages to using clones. They can be found at your local dispensary, come from a proven genetic lineage and generally do well outdoors, making them the ideal choice for inexperienced growers. On the other hand, the clones develop a fibrous root system, unlike the deep roots that develop with seeds. Fibrous root systems can reduce their ability to cope with environmental stress and predatory insects.
Whether from seed or clones, many growers begin growing their plants indoors to ensure that they are not exposed to excessive weather conditions as they develop their initial root system. Plants are processed outdoors when weather conditions and photoperiods, or times when a plant is exposed to light, are ideal. Extending the growing season indoors can help increase yields and give growers time to select the best plants to move outdoors.
Media and Containers
There are many options when it comes to soil types and how you can plant your cannabis plants outdoors.
Quality soil should be dark, rich in nutrients and have a light, fluffy texture. The structure of your soil should be able to retain water while allowing for excessive drainage. Organic potting soil mixtures from your local garden centre will do very well, but more advanced growers prefer to mix their own organic potting soil from scratch. The soil itself should be slightly acidic with a pH of about 6, which can be tested with a pH meter or soil test kit.
Container gardens can be convenient as they can be moved around the garden to maximize sunlight or protect them from harsh conditions such as rain, high winds, or extreme temperatures.
Avoid clay pots as they can be expensive, heavy and retain heat that could dry out the soil and plant roots. Cloth pots are the cheapest and most effective solution because they provide good drainage and plenty of oxygen to reach the roots. Plastic containers are also lightweight and inexpensive, but tend to retain more heat than fabric pots. Flowering plants need a container of at least five (5) gallons, or 18.9 litres, or larger to prevent plants from sticking out of the container and becoming attached to the roots.
Planting directly in the ground or in an elevated bed requires a little more preparation, but also has its advantages. Without a container to restrict growth, the roots can grow deep and thick to support a strong plant. Adding surface area also allows the plant to access more nutrients and water in the soil compared to a container garden. The main disadvantage is that the plants cannot be moved and may require additional structures to protect them in extreme weather conditions.
Cannabis needs more nutrients than most of the common plants you may have in your garden. Good soil contains enough organic nutrients to start the growth cycle, but as your cannabis plant grows and blooms, it may deplete the available nutrients and require additional fertilizer.
The three main nutrients needed to grow marijuana are nitrogen, phosphorus and potassium.
During the vegetative phase, plants need more nitrogen than during the flowering phase to create the roots and leaves that serve as the basis for flowering. At the beginning of the flowering cycle, plants will need more phosphorus and potassium than nitrogen. Towards the end of the flowering cycles, once most of the nitrogen has been used up, the plants will focus their attention on using the remaining nutrients. Lack of nitrogen is largely responsible for the bright purplish and orange hues that can be seen on the large fan leaves and in the colas of the plants.
Avoid all-in-one fertilizers as they may be too rich in nitrogen for the flowering cycle and damage any beneficial microorganisms that may be present in the soil. It is suggested that you choose a range of nutrients created specifically for cannabis and use their suggested feeding tables to avoid over- or undernutrition. Organic sources of nutrients are usually preferred because they are an excellent source of beneficial microbes, but they may take longer to break down and become available to the plant. Both types of nutrients can be found in premixed dry powders or liquid emulsions, but can also be prepared from scratch with the right ingredients.
Organic sources of nutrients include alfalfa meal, bone meal, kelp meal, bat guano, fish emulsion, dolomite and earthworm castings. Each contains different nutrient ratios that can be used for different phases of the plant growth cycle.
Watering and Feeding Plants
The amount of water a plant needs depends largely on its size, the size of its container, the type of soil and general environmental conditions such as the weather and intensity of the sun. Taller plants and warmer environments tend to use more water than smaller plants and cooler weather. The amount of water varies throughout a plant's cycle.
During the vegetative phase, your plants should be watered thoroughly, waiting for the top one (1) inch, or 2.54 centimetres, of soil to dry. This can be every day or every four days, depending on conditions, but the time between watering cycles will be shorter as the plant grows its roots. Container gardens tend to dry out faster than soil beds, so they will need to be watered more often.
Withering plants and dry soil are a direct sign that plants need water. Falling leaves and wet soil are a sign of over-watering. Both of these errors are common and can be corrected with a little practice.
For a small garden, hand watering is the easiest and cheapest way to water plants. It also allows you to become familiar with the needs of each cultivar and to give each plant the exact amount of water it needs. Irrigation systems can be suitable for a large number of plants or for times when you can't be in your garden.
Pest and Weed Control
Pests and wild plants are unavoidable when grown outdoors. Most problems can be avoided with good planning. Clearing a buffer zone around your plants can go a long way, but your first line of defence is a healthy plant that can defend itself naturally.
Pests come in many forms, from large deer and gophers to small slugs and spider mites. Larger animals and pets can be kept away from the garden with fences, while gopher wire under your soil beds can prevent rats and gophers from eating plant roots. Weeds won't damage cannabis, but they can compete for soil nutrients and reduce the quality and yield of your crops. A light layer of mulch on your soil can prevent other weeds from germinating in the middle of your cycle.
Avoid spraying synthetic insecticides on your cannabis plants, as more research is needed to determine the health effects of smoking plants treated with synthetic chemicals. Organic pesticides and insecticide solutions can be effective if used properly. If you can avoid it, it is always best not to spray anything on your plants while they are flowering.
Beneficial insects, fungi and bacteria can also be used to protect your plants from their less beneficial counterparts. Jumping spiders, ladybugs and other native predatory insects can rid your crop of insects such as aphids and whiteflies. When looking for beneficial insects, fungi or bacteria, it is important to look for those that are native to your area.
Even if it is legal to grow your cannabis outdoors, you should still take certain precautions to hide the plants from public view. You can grow your cannabis plants among other common plants in your garden and try to hide them from public view. Cannabis can easily grow larger than the average fence. Training techniques can help you to keep your plant shorter. The fewer people who know you are growing cannabis, the better.
Greenhouses can be an excellent middle ground between the complexity of an indoor facility and the uncertainty of growing outdoors. They provide adequate protection from the elements and use far fewer resources than an indoor operation. Greenhouses can be more expensive than an outdoor garden and require more planning, but they also allow you to extend the growing season considerably.
Greenhouses also offer growers the opportunity to harvest more than one cycle per year if equipped with a light deprivation system. These systems allow growers to control the hours of sunlight their plants receive, much like turning lights on and off in an indoor garden, by covering the greenhouse with a black tarp that deprives the plants of sunlight.
Greenhouse structures range from inexpensive polyvinyl chloride (PVC) tubing, often called "hoop houses", to highly designed, fully automated, custom-built steel greenhouses. Because of their efficiency, greenhouses are quickly becoming the preferred growing method for many large-scale growers.
Tips for success
The smallest adjustments can make all the difference - planting a week earlier, a week later, watering less, watering more, and so on.
Quality soil is crucial to the success of your crop and one of the few factors you can control outdoors.
Timing is the key. A short vegetative phase can cause cannabis plants to flower early, while a long vegetative phase can prevent your plants from completing their flowering cycle if the weather deteriorates. The Farmer's Almanac is a reliable source for planning the seasons and preparing your harvest for success.
Practice makes perfect, so always keep a crop diary and be sure to note any mistakes along the way. Keeping a record can ensure a successful future harvest.
“Larsen, Lucas. “The Cultivation of Weed.” Nature, vol. 525, no. 24, Sept. 2015.
United States Department of Agriculture, Natural Resources Conservation Service
Burke, Anthony. “Cannabinoid Biosynthesis Part 1 – CBG, THC, CBD and CBC.” www.marijuana.com, 23 June 2014.
Fellermeier, Monica, et al. “Biosynthesis of cannabinoids: Incorporation experiments with 13C-Labeled glucoses.” European Journal of Biochemistry, no. 268, 2001, pp. 1596–1604.
ElSohly, Mahmoud A., editor. Marijuana and the Cannabinoids. Humana Press, 2007.