How to increase terpene levels in cannabis plants
To many cannabis growers the most important challenge is maximising cannabinoid content in general, and THC levels in particular. But to cannabis connoisseurs there is something just as important, terpenes. Terpenes are the aromatic compounds that give the exotic and exquisite aromas to your buds. Great cannabis becomes simply unforgettable when it has a high terpene content!
Terpenes are mixed with the cannabis oils and cannabinoids in the glittering trichome resin glands which coat the buds and leaves. A rich terpene content gives your cured buds an unbeatable, desirable and tempting aroma. Cannabis terpenes are also thought to modulate (or ‘steer’) the type of high you experience. Terpenes such as myrcene may even contribute to the physical effects of cannabis thanks to it’s anti-inflammatory properties.
Conversely, cannabis with a poor terpene profile smells bland, unappealing and unworthy to be in your stash. Read on to find out more about optimising the terpene levels in your next cannabis grow and take a peek at some Dutch Passion lab analysis reports so you can see the science behind the numbers.
Key differences between terpenes and cannabinoids
Cannabinoids are a family of compounds found in cannabis. The most well known of these is THC (Tetrahydrocannabinol, psychoactive). CBD (Cannabidiol, non psychoactive) is another well known cannabinoid. The total number of cannabinoids is thought to number at least 113.
Many of the cannabinoids are being intensively researched for their potential medical uses by Pharmaceutical companies. Dutch Passion have pioneered cannabis seeds rich in novel cannabinoids such as CBG, THCV, CBDV and others:
|Dutch Passion special cannabinoid cannabis seeds|
Terpenes are a different class of natural compounds more closely associated with their fragrant and aromatic properties. They are found in many plants, not just cannabis. Limonene is found in citrus plants (and cannabis!). It produces a lemon/citrus aroma.
|What is Limonene and what does this cannabis terpene do?|
Many cannabis connoisseurs love a deep, rich terpene profile on their cannabis, feeling that it enhances the effects of the THC. Pinene is a terpene found in Pine and conifer trees, it gives a fresh ‘forest’ aroma.
|Everything you need to know about cannabis terpenes|
One other important cannabis terpene is known as beta caryophyllene. Also known as caryophyllene, it can account for up to/around 25% of the total terpene content in the cannabis plant.
|What is Beta Caryophyllene and what does this cannabis terpene do?|
What are the highest cannabis terpene levels?
The final terpene content in your cannabis depends on several factors. These include your original cannabis seeds and the genetics which they contained, as well as the way the cannabis was grown and cured.
Usually, in cured buds, the total terpene content is up to 0.5% of the total weight. However with the best genetics and optimised grow/curing conditions you can see terpene levels around 1% of the bud weight.
The following terpene analysis from Auto Skywalker Haze showed the total terpene content to be around 1%, higher than the terpene levels found in ‘average’ cannabis strains. Interestingly, the analysis showing these high terpene levels came from a plant that gave a stunning record level of 26.2% THC as well.
How to increase terpene production in cannabis
The most important advice is to start with premium quality cannabis seeds. Even the world’s best growers can't produce top-shelf buds from low-grade genetics. You need to aim for the best autoflower seeds / feminised seeds with an optimised grow room.
You will also need to ensure optimised nutrition throughout the grow, avoiding over feeding or under feeding. Below are some of our top suggestions to increase terpene production in your next cannabis grow.
Choose terpene-rich cannabis seed genetics
The price difference between the best cannabis seeds and mediocre seeds is usually just a few Euros/Dollars/Pounds per seed. Yet the difference in terms of the value of the final crop can be dramatic. Starting with the finest cannabis seeds you can buy is the best place to begin any cannabis grow.
Know when to harvest based on trichomes
Cannabis terpenes are found in the trichome resin glands. For maximum potency, you want to avoid harvesting too early and too late. Harvest too early and the plant biochemistry won't have finished maximising the terpene and cannabinoid content. Harvest too late and the trichomes start to take on an amber appearance as they (and their contents) start to degrade.
|When to harvest cannabis|
Control the light cycles and intensity at all time
Optimised grow room lighting is neither easy nor cheap. Professionals tend to insist on LED lights rather than HPS. Quality levels from LED are inherently higher than HPS with improved potency and taste. The higher prices charged for the superior quality harvests soon repays the initial purchase cost of the LED lights.
Professional growers usually ‘map’ light intensity across the grow room, adding extra lights in areas with low light levels. Probably the best single grow room upgrade that any cannabis grower could make would be a good quality LED grow light. Good manufacturers will recommend correct hanging lights for various growth stages.
The value of organic nutrients
Many growers insist on the use of organic nutrients to produce the most flavoursome buds with maximum bag appeal. Organic nutrients are often used by many of the higher quality growers known for terpene packed buds. Not only does the natural approach produce rich, deep flavour/aroma, but it can also simplify nutrition greatly.
Under feeding and over feeding (especially from less experienced growers) are two of the most common reasons that plants are stressed and subsequent harvest quality is compromised. When using an organic nutrient range, such as those from BioTabs, you often only need to ‘feed’ your plant with water. The slow release organic nutrients allow the plant all the nutrition they need.
Not only can organic nutrients contribute towards a great terpene profile, they can improve the final harvest quality by helping you keep your plants in the nutrient sweet spot throughout the grow.
Quality organic, living soil
Organic purists will tell you that nothing is as good to grow cannabis in as a high quality organic living soil. ‘Living’ means that it is rich in bacteria, fungi, protozoa, nematodes, arthropods, and even earthworms. All of these continually breakdown material for use as nutrients by your plants and for many growers it is a natural way to maximise taste and cannabis terpenes.
Lower night temperatures in bloom and flushing
Many believe that using lower temperatures during the evening in bloom help preserve the terpenes in your plant and prevent the volatile compounds from disappearing down your air extraction pipe. Some growers also feel that flushing your cannabis is essential to remove excess minerals and nutrients, therefore improving taste.
However, not everyone agrees with flushing, feeling that it deprives plants of key nutrients during the final crucial stages of life.
Low stress and cannabis terpene increases
Some growers feel that a little bit of plant stress is a good thing when it comes to cannabis cultivation. The logic is that low stress levels e.g. from training/tying down your plants (or even defoliating) can produce enough stress to improve terpene levels without it detracting from overall plant health.
|Cannabis low stress training (LST), how to do it and why|
Master the art of curing cannabis
Slowly drying and patiently curing your cannabis is the best way to retain as many of the precious terpenes as possible. Dry your cannabis in conditions that are too hot and you will lose most of the tasty terpenes. Never consider ‘speed drying’ your crop or drying it in bright light (e.g. in your grow tent with the lights on) if you are aiming for top-shelf quality.
|How to harvest, dry and cure your cannabis|
Consider UVA & UVB light supplementation
Other than the sun or plasma lights, relatively little UVA & UVB can typically be found in your grow room lights. If you’re growing with LED, ceramic metal halide or HPS then your grow room may benefit from the addition of a supplemental UVA/UVB light.
Many believe that UVA/UVB increase terpene and cannabinoid content. Some recent analysis of clones bloomed with and without UVA/UVB have shown terpene levels increase by up to 50%. The UVA/UVB light was a Migro UVB 310 fixture.
Increasing cannabis terpenes with blue light treatment
Many growers try to increase the amount of cannabis terpenes using blue light treatment. This is where a blue-dominant light spectrum is used for the final few days of bloom. Blue light does little for yields, though by the end of blooms should already be fairly chunky.
However blue light is thought to allow your plants to focus their biochemical energy to produce increased amounts of terpenes. Some commercial growers use e.g. blue-dominant ceramic metal halide (‘CMH’) for the last few days to increase cannabis terpenes, and therefore the commercial value of their crop.
Those with spectrum-adjustable LED grow lights (Grow Spec, California Lightworks etc) are also able to utilise the blue light treatment. The red LED’s are simply switched off allowing the plants to enjoy the blue light treatment for the last few (e.g. 2-3) days.
Effect of blue light treatment on Auto Cinderella Jack, 21% THC and 1.6% total terpene content
A great deal of recent research Dutch Passion research has been focussed around the area of maximised THC levels on elite autoflower seeds such as Auto Cinderella Jack.
Until the recent 26%+ THC levels seen on Auto Skywalker Haze, the 25.9% THC levels seen on Auto Cinderella Jack were the highest ever seen by Dutch Passion. One interesting observation has been the fact that high terpene levels (around 1% or more of the total dry buds) are often seen when plants have been grown in optimised conditions. This allows cannabinoid profiles to be maximised as well as terpene levels, indicating that the quality genetics have been allowed to grow to their full potential.
The lab analysis chart (below) was from Auto Cinderella Jack grown with blue light treatment for the final few days. Note that the total terpene content in the cured buds was 1.6%. This is a particularly high terpene content, perhaps 3-4 times that seen in lower quality grows. Note also that these very high terpene concentrations accompanied 21% THC levels in the buds. This is proof that the best genetics can deliver extreme THC levels as well as unbeatable taste and aroma.
Most connoisseur growers will tell you that you need to buy the best cannabis seeds to produce the highest quality harvests. But you also need to cultivate them well! That means optimised lighting, nutrition and environmental conditions as well as quality starting genetics.
Best cannabis seed terpenes profile
Optimising your grow conditions, lighting and cannabis genetics is the best way to improve overall plant health as well as maximising cannabis terpene content and overall cannabinoid levels. You also need to consider nutrients and your attitude towards a possible organic approach as well as learning how to deliver the best drying/curing conditions.
In an ideal world, most hobby growers want to aim for maximised THC levels alongside genuinely intense, deep aromas that make you gasp with delight as you open your jars.
For some growers, the type of aroma is particularly important.
• The Orange family of cannabis seeds is known for their sweet, citrus scented buds.
• The Skunk cannabis seed collection are notorious for their incredibly potent, penetrating terpene profiles which give incredible taste.
• USA Special cannabis seeds boast perhaps some of the loudest flavours and terpenes!
• Afghani Kush cannabis seeds often give rise to some rich, deep hash scents
• Blue family cannabis seeds enjoy delicious fruit and dark berry tastes, terpenes to die for!
One other interesting observation for cannabis terpenes has been the unusually high terpene profiles for some of the new, Special cannabinoids cannabis seed collection.
Recent lab analysis charts have shown that nearly all the cannabis samples taken from THC-Victory (the world’s first commercially available THCV rich strain) show terpene levels of around 1% in the cured buds. That’s around double the average and perhaps an indication that some of these new special cannabinoid genetics also produce inherently high terpene profiles.
But whichever type of cannabis seeds you buy, aim to grow them to the best of your ability and do all you can in your grow room to optimise your conditions. That includes humidity, PPFD light levels, nutrient management, temperature control and all the usual factors which affect the growth of your plants. Master the art of maximising your terpene profile and you will savour new quality levels in your next harvest!