Top O' the season to ya! Here in the Grower’s Grove last month, we started to look at the relationship between the aromatic compounds, or terpenes, in Cannabis and the other active compounds such as THC and CBD. Current research shows that terpene compounds play a significant role in altering the effects of medical cannabis. The amazing range of different effects from varying types of cannabis can now be seen in a framework much larger than basic cannabinoid ratios or a simple sativa vs. indica dichotomy. In addition to these factors, how the plant smells affects the character of the medicinal effects – sometimes quite significantly. Since aromatic compounds are already capable of producing physical effects in small amounts simply by being inhaled, the process of cannabis patients sniffing varying jars in a dispensary to help determine which strain to get may be a more complex relationship between patients and their medicine than previously thought.
That Which You Give Attention To, Grows.
With so many things in life, getting what you want depends first on knowing what you're looking for. Such is especially the case when it comes to breeding Cannabis. While many accidental hybrids turn out to be good strains, most world class Cannabis strains are the result of a veteran grower who knew what they were looking for. Now that the Cannabis community has become aware of the role of smell compounds in the medicinal effects, breeders can start to give attention to associating the effects of each strain with it's smell profile. In addition to other breeding factors such as flowering time and yield, growers have the ability to combine aspects of differing varieties based on the character of the effect. Perhaps strains that have a similar effect between them but varying flowering times, colorations, etc. could be combined to reinforce the trait of the smell profile while strictly altering other growth variables.
For instance, From Marijuana & the Cannabinoids1:
“The terpenoid compounds found in Cannabis resin are numerous, vary widely among varieties, and produce aromas that are often characteristic of the plant’s geographic origin. Although more than 100 different named terpenes have been identified from Cannabis, no more than 40 known terpenes have been identified in a single plant sample, and many more remain unnamed (11). Terpenes are produced via multibranched biosynthetic pathways controlled by genetically determined enzyme systems. This situation presents plant breeders with a wide range of possible combinations for developing medical Cannabis varieties with varying terpenoid profiles and specifically targeted medical uses. Preliminary breeding experiments confirm that the terpenoid profiles of widely differing parents are frequently reflected in the hybrid progeny.”
The 2 most important parts of this excerpt are the references to developing strains for “specifically targeted medical uses” and the last line that basically states that the smell profiles are genetically controlled and that combining “widely differing parents” can yield terpene profiles that encompass both parents. For instance, a lemon-flavored haze crossed with heavily pine-flavored OG Kush can yield a piney-lemon flavored seedling. If each of those compounds separately had a specific medical effect on their own, then the combination of the two could yield a medicine that ideally suited patients that had both ailments. That having been said, there are many genetic factors involved in breeding and seedlings will still have a wide degree of variance. With any cross, the hardest part is seedling selection and it will always be necessary to sprout as many individuals as possible in order to find the one that came together in the way the breeder intended. Once that individual is found, it's genetics and the terpene profile that it's programmed to make need to be cloned in a stable vegetative environment where the genetic integrity is retained. (See my previous article “Cloney Baloney” available on my website JadeKine.com for more info on seed selection and keeping long-term mother stock.)
Preliminary Terpene-Cannabinoid Studies
Marijuana & the Cannabinoids continues:
“Early Cannabis medicines were formulated from alcoholic whole flower or resin extracts and contained terpenes, although they were not recognized to be of medical importance. Several of the monoterpenes and sesquiterpenes found in Cannabis and derived from other botanical and synthetic sources are used in commercial medicines. Other as-yet-unidentified terpenes may be unique to Cannabis. The highly variable array of terpenoid side-chain substitutions results in a range of human physiological responses. Certain terpenes stimulate the membranes of the pulmonary system, soothe the pulmonary passages, and facilitate the absorption of other compounds (15). Terpenoid compounds are incorporated into pulmonary medical products such as bronchial inhalers and cough suppressants. Casual studies indicate that when pure THC is smoked, it produces subjectively different effects than it does when combined with trace amounts of mixed Cannabis terpenes.”
Preliminary studies seem to validate the theory of terpene-cannabinoid interactions. In one such casual study, participants evaluated 3 identical samples of product - one without any additions to it, one sample with food grade limonene added and one sample with beta-caryophyllene added. When beta-caryophyllene was added to the sample, participants reported an increase in “body effects” such as pain relief and reduction in inflammation. In fact, unlike other terpenes, Beta-caryophyllene binds with CB2 endo-Cannabinoid receptors directly. In essence, it acts like a cannabinoid in the body, but only on one set of receptors, thereby altering the effect. When limonene was added to the sample, anti-depressant effects were reported. The anti-depressant effects of limonene have been well documented and perhaps help explain how citrus is one of the most commonly looked-for smells in Cannabis strains (lemon, grapefruit, orange, etc).
How to Protect your Fragile Flavors
For all that terpenes are capable of, they're still quite delicate when it comes to temperature. While the plants are alive and growing, the transpiration of the plant cools the resin to a certain degree, but once the plants and the resin are dry, terpene compounds begin to volatilize at temperatures as low as 75 degrees F. That means that drying and storing your Cannabis at cool temperatures is a must when it comes to keeping that flavor locked in. This is also an important factor when it comes to laboratory testing. Only the High Performance Liquid Chromatography, or HPLC, method of testing is capable of accurately assessing terpene profile because it is done at room temperature without combustion. By using pure terpene compounds (many of which are commercially available) as a standard to test against, the HPLC method can accurately determine exact concentrations by dry weight of terpenes in the sample.
With so much selection being done according to standards that aren't very rigorous, (like if you cross the Green Crack with the Trainwreck for no other reason than to call it the “Charlie Sheen,” that would be a less-than-scientific approach) it is important for breeders to be thoughtful about crossing the right plants based on what smells and effects have the most benefit for patients. Every cloned seedling deserves it's own name anyhow, so don't worry about crossing things based on name or popularity alone. Look for traits you like in each strain and try to combine them based on what will compliment the other one. Remember, genetic diversity is key. Short term crazes for purples or OGs threaten genetic diversity. Clubs that only carry hybrids of one strain threaten bio-diversity in the market (ahem...OG anyone?). Maybe there were many unique strains in that area before all the growers got rid of them to select for only things crossed with OG Kush. Hopefully, the advent of laboratory testing will help educate both consumers and budtenders with more accurate profiles of the medicinal effects than is currently available.
In next month's Grower's Grove, we'll look into some cutting edge research that breaks down commonly grown strains by their terpene profiles. Until then, take a deep breath of your favorite flavor and remember that finding what you want is about knowing what you're looking for.
-Jade Kine
(Growers Grove writer Jade Kine is a former greenhouse manager for the medical Cannabis industry with over a million plants worth of growing experience. He is also the founder of CannAcademy (www.CannAcademy.com), a trade school dedicated to horticultural training for growers. Got a question for Jade? Drop him a line at This email address is being protected from spambots. You need JavaScript enabled to view it. Complete bio and previous articles at www.JadeKine.com Facebook/Twitter: @JadeKine)
