Terpenes are the plant compounds that cannabis cultivators, aficionados, and consumers have to thank for the vast variety of flavors and aromas that give each strain its first indelible impression.
Terpenes play an important role in plant interactions, plant defenses, and the way that a plant adapts to everything it is bound to encounter in the fight for survival and thriving in a natural environment. Terpenes and other plant signalling molecules mediate the growth and developmental processes of a plant, allowing it to grow and reproduce successfully. They are involved in the promotion of inhibition of seeds taking root and germinating, the inhibition of root or stem growth, flowering and fruiting, and control whether a plant’s cells divide or go dormant until better conditions arise.
Lower levels of terpene concentrations in plants have been highly correlated with higher risk of susceptibility to environmental stressors. It seems that terpenes play a vital role in helping plants stand up to the harsh realities of unpredictable weather, tough regional climates, and variable growing conditions.
While terpenes can be found throughout the plant, the sticky resin that is secreted off the trichome glands of a cannabis flower contain a highly concentrated amount of terpenes (and cannabinoids), further explaining why cannabis buds are so much more effective in their benefits than, say, the stems or stalks.
For a more in-depth look at the terpenes that can be found in THC Design’s strains and in other cannabis plants, check out our articles on primary and trace terpenes.
Terpenes run the gamut in flavor profiles from spicy and peppery to floral and piney. They are the tiny molecular culprits behind the pine smell in deep, green forests, and the wonderfully relaxing scents of lavender or citrus plants.
And while each terpene has a distinct smell and flavor that it is associated with, each terpene is usually host to a number of therapeutic and clinical properties that, when crossbred with the right sister cannabinoid and terpene profiles, can result in truly amazing cannabis strains that provide a powerhouse of medical benefits to the mind and body.
While it’s certainly undeniable that the relationship and synergy between the primary cannabinoids, THC and CBD, and terpenes results in enormous benefits therapeutically, there is a delicate science and art to manipulating the terpene concentrations that can result from any one harvest.
While the baseline genetics of any one strain are definitely unavoidable, the influence of the environment on any one harvest or any one crop within a harvest can make all the difference. The easiest parallel to draw is with an industry that is oftentimes called upon to help bring cannabis cultivation and appreciation into the mainstream — viticulture, or the science of wine.
Just as is the case in our carefully bred and cultivated cannabis strains, the terpene profiles of every wine grape play a monumental role in giving a glass of wine from a particular region and particular year its distinct flavor profile.
So how does one go about manipulating terpenes when there are already set terpenes that are available in a genetic code for a grape or a bud?
Whether you might’ve guessed it or not, the answer is stress. It turns out that with a little bit of knowhow about terpenes and how abiotic, or nonliving, stress factors relate to one another, survival of the fittest can be hijacked to produce some of the most flavorful, rich, and nuanced wines and cannabis available today.
Plants are designed in every way to literally deal with the stresses of everyday life. While the plants that we grow in our state-of-the-art greenhouses at THC Design might have the luxury of never inadvertently going hungry or thirsty, plants in the natural world are constantly up against a host of external stresses that must be dealt with.
Abiotic stresses can include everything from a lack of water or nutrients such as iron and phosphorus to vine stress caused by the presence of insects or other pests. Abiotic stresses can mean too much salt in the soil, or too low a pH level.
At a cellular level, it has been demonstrated that under various types of stress, plants trigger a variety of responses that lead to increases in the production of terpenes since these phytocompounds play an important role in the actual mechanism and processes of the plant. Their aromatic properties could almost be considered coincidental!
And yet, here we are in that lucky nexus of science and beauty where a plant’s natural ability to respond and adapt to its environment comes hand in hand with that particular plant’s special brand of flavor and scents as a direct result.
Under a certain level of controlled stress, a cultivator can push his or her plant to grow less foliage and more flowers. This is a fine balance though, as pushing the plant to expend too much energy towards flowering can mean an overabundance of bud that dilutes the given concentration of terpenes that are available at harvesting. Alternatively, pushing a plant to flower less in the hopes that each bud packs a bigger punch will mean that the plant expends too much energy in developing its canopy of leaves, leaving the buds underdeveloped and without flavor.
In an outdoor growing environment, cultivators manage the stress of varying environmental conditions through careful pruning, disease management, and sunlight exposure. In an indoor environment, growers have more freedom to actually expose their plants to a small amount of controlled stress in order to promote flowering growth and inhibit too much vegetative growth in order to obtain the perfect balance of flavor and potency.
Pruning the canopy back (or choosing to let it grow for a longer duration of time) gives the cultivator control over the amount of sun exposure that reaches a plant. Increases in sunlight exposure and temperature tend to lead to increases in terpene production, as the stress of light and heat stimulate the plant to trigger its usual defense mechanisms in protecting the plant.
Cutting back a plant’s less desirable stalks in favor of more vigorous or better fruiting stems will also lead to an increase in terpene production, as a plant’s natural response to injury is to promote more growth.
Another tool for managing stress is controlling the amount of water that is available to the plant. This can include moisture in the soil as well as the humidity levels of the plant’s immediate growing environment. In the wild, lack of water can damage plant cells by sucking them dry and making the cell walls brittle and damaged. This can lead to decreased growth, wilting, and damage to the roots and leaves. Conversely, too much water can reduce the amount of oxygen available in the soil, leading to root loss and injury, not to mention a much higher risk of fungal infection.
But preventing cannabis plants from having all the water they can drink up is a fantastic technique for pushing plants to produce incredible flavor in a totally different way. Dry farmers in viticulture will reduce the amount of irrigation that they use on their wine plants to push the plants to grow deeper roots that have to work harder in pulling nutrients and moisture from the soil, subsequently bringing the region’s particular flavors of the earth straight into the lifeblood of the plant. Terroire article.
And lastly, while insects exerting pressure on stalks and leaves will lead to increases in terpene levels, it’s a highly risk form of stress management since insects can in fact bring a host of diseases and problems that can invariably destroy a whole crop. Needless to say, most cultivators won’t expose their plants to certified pests in an effort to boost terpene production when accurate and precise knowledge about light, water, and nutrients will do the trick beautifully and harmlessly.
Our knowledge of the regulation of terpene synthesis, metabolism, and signalling in the plant allows cultivators to directly manipulate the concentration of terpenes in wine grapes or in cannabis buds.
All in all, the grower and the practices that he or she uses can have a large impact on the style of cannabis that will be produced and the quality of bud in terms of color and flavor potential. And a little stress is a good test of the health of plants — a robust and vigorous plant should be able to withstand a little bit of forced stress from time to time.