Growing for Terpenes

Growing for Terpenes

When asked by a close friend Ellenthe editor-in-chief of this publication will resume writing. high times I jumped at the request. As a journalist, educator, and lifelong student, I have always enjoyed diving into the topics covered in this journal over the years and revisiting certain subjects as new science becomes available. Here we examine the cultivation of cannabis specifically for terpene production.

Terpenoids, or terpenes, are one of the most important compounds produced by cannabis plants. These are the compounds responsible for the plant’s aroma, giving each variety its unique scent. Terpenes, like cannabinoids, are produced in plant trichomes. Trichomes are small appendages that extend from plants and are found not only on the buds of plants, but also sometimes on the leaves. In cannabis plants, it usually consists of a stem and a head. Inside these heads are most of the essential oils found in the cannabis plant, including cannabinoids, terpenes, flavonoids and other compounds.

There is now a shift in dialogue around the percentage of THC and its sole importance in selling cannabis in many legal markets around the world. This should be taken as great news for consumers. Consumers ultimately benefit from more knowledge about plants and how their active compounds interact to induce effects. This became known as the entourage effect. THC is like gasoline in your car, and terpenes and other compounds act like GPS, giving direction to your high.

high times magazineMay 2023

The first researchers to discuss the entourage effect were Dr. Raphael Mechoulam and Dr. Shimon Ben Shabbat. They proposed that the combined effects of all the compounds contained in the trichome heads work in “plant synergy” to maximize the pharmacological effects of cannabis. This concept was further extended by Dr. Ethan Russo in his 2011 paper. British Journal of Pharmacology“The interactions between the phytocannabinoids and terpenoids found in cannabis provide complementary pharmacological activities that may enhance and expand clinical applications and improve the therapeutic index of cannabis extracts,” said Dr. Russo. I wrote.

This argument reflects improvements in cannabis cultivation, showing that the proportion of phytocannabinoids and terpenes has risen to incredible levels. Some strains reach a total cannabinoid content of 35-38%, and it is not uncommon for some flowers to reach a total terpene content of 5.5-6%. As cannabis research progresses, cultivation techniques are becoming more and more sophisticated. Using a science-backed approach, growers can test their flowers and make real-world adjustments to their environment, nutrient use, and genetics. When growing for terpene content, the main factors a grower can control are nutrients, ultraviolet (UV) light, temperature control, harvest schedules, drying/curing processes, and genetics.


Nutrients, especially certain plant hormones such as methyl jasmonate, can stimulate systemic acquired resistance (SAR) in plants. This makes it necessary to increase natural oils, in this case terpenes, flavonoids and cannabinoids, as a protective measure. Another way to access this reaction is called salicylic acid. An article published in a magazine Food Science and NutritionA team of botanists from Urmia Medical College in Iran found that using salicylic acid as a foliar feed can increase the production of cannabinoids, flavonoids and terpenes. When sprayed on cannabis plants, the acid modulates the jasmonate signaling pathway naturally found in cannabis. This makes the synthesis of flavonoids and terpenes more efficient, increasing their values ​​by a few percent. The most well-known nutrients used for terpene fortification are terpinator. This product does not contain methyl jasmonate or salicylic acid, instead the main ingredient is potassium (K), which increases the activity of enzymes and makes essential oil production more efficient. Another product on the market is FlaVUH. Ventana Plant Sciencewith a proprietary polyaspartic acid amino acid that increases nutrient uptake to plants, increasing yield and natural oil production. It also does not contain jasmonate or salicylic acid.

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ultraviolet rays

We know that UV light not only increases cannabinoids, but also has a significant impact on terpene production. This stems from the fact that plants naturally protect themselves from UV rays by increasing the production of essential oils. One of the most interesting advances in cultivation is the improvement in the quality of LED lights. In recent years, LED fixture companies have added UV diodes to their lighting fixtures, which has increased cannabinoid and terpene values. A long-standing question about the benefits of growing outdoors versus indoors has now emerged with new evidence supporting the benefits of UV a diary molecule A group of scientists from Columbia University worked with several growers in California to test the difference between outdoor and indoor cultivation. Using the same clones, media, and nutrient regiment, they grew the plants in outdoor farms and under artificial lighting. Their findings showed that not only were terpenes and cannabinoids high in outdoor grown plants, but also unique terpenes and trace amounts of cannabinoids were detected in outdoor grown plants. Furthermore, the proportion of sesquiterpenes such as b-caryophyllene and α-humulene was higher in outdoor plants. We can speculate that these terpenes are more present in outdoor plants because they need more UV protection.

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temperature control

Temperature control is another important factor in terpene production. Typically, lowering the temperature at the end of the flower cycle also increases terpene production. Usually going down to 5-10 degrees Fahrenheit will fix the problem. An additional benefit of lowering temperatures is that flavonoid production is also increased, increasing the amount of color present in the buds of plants that are naturally purple.

harvest schedule

Since the advent of cannabinoid and terpene testing labs, the harvest schedule has become a very easily controlled factor. In the past, people had to rely on loupes and magnifying glasses to study the colors of trichomes. You can now test flowers at any point in the harvest cycle and choose the moment of perfect ripeness according to your needs. Generally, for terpene production, it should be harvested a little earlier, while for THC, it should be harvested a little later in the cycle.

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drying and curing

Drying and curing are processes as important as growth. Most people forget that nine weeks of work can easily be ruined by improper treatment or storage. Especially in cities like Denver, the high altitude makes the flowers dry out easily. My preferred dry environment is a cool environment of 45-50 degrees Fahrenheit and about 55-60% relative humidity. I also like to keep the fan leaves on the plant as well as keeping the plant as intact as possible. This will dry the cannabis at the slowest possible rate and preserve the essential oils. For storage, glass is always better than plastic unless you can nitrogen flush or vacuum seal the bag. The key to preserving flowers is to keep the jars full. Choose a jar large enough to fill to the top, as the space at the top of the jar (the natural space between the lid and the flower) allows the terpenes to evaporate more slowly. Some people love humidity control packs. I have personally found that they trigger a reaction to some of the more volatile terpenes, resulting in a more uniform flavor across different cultivars. We recommend investing in research and testing flowers before and after using moisturizing packs to see if they work.


Finally, genetics may also play an important role in terpene-rich flowers. The key here is to try the environment and keep testing. Test which breed works best for you, your environment, and the nutrition program you’re using. Science is your friend here. Get the most out of your cannabis testing lab. Remember that science is based on evidence, not belief. So science can help us learn more about flowers and the compounds they contain. This allows you to grow the wettest, loudest, and most powerful flowers. May the terpenes be with you.

This article originally appeared in the May 2023 issue of the magazine. high times magazine.

Chris M.

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