LED Lights and Cannabis Quality: What You Need To Know

Growing a lot of cannabis is always a good goal to have in mind as a cultivator, but quantity is not always better than quality. The quality of Cannabis helps determine its price point, and to determine quality cultivators must look towards a crop’s secondary metabolites. These include terpenes, pigments and cannabinoids, the stuff that not only gives cannabis its potency, but its flavor, color, and even vibe, as well. There are many factors that go into developing strong diverse flavor and potency profiles, from PH of soil to amount of stressors in the environment, but it should come as no surprise that one of the best things a cultivator can do for their plants is to deliver a wide range of photons through a professional lighting system.

Here is what you need to know about how your LED grow lights can affect cannabis quality.

ACCESSORY PIGMENTS

While it may not bear the same significance as overall yield, the color of cannabis has a huge influence on whether or not someone will buy it. In fact, 93% of cannabis smokers noted that they’ve been influenced by the color of a strain. These colors, or pigments, are actually great indicators of the conditions under which the plant was grown, the quality of the light it received, and transitively, its potency.

Let’s look at some of the most prominent accessory pigments.

Carotenoids

Carotenoids are compounds that are responsible for producing the red, orange, and yellow colors in plants. These are synthesized by all green plants but are often masked by chlorophyll. In the fall, chlorophyll will begin to degrade, but carotenoids will stay a bit longer, which is why you see a lot of orange, red, and yellow around that time of year. These pigments absorb the blue-green light that is otherwise reflected by the green plants, and are responsible for the beautiful orange hairs in cannabis that buyers covet.

Flavonoids

Flavonoids are essential for photosynthesis. While it’s theorized that plants produce flavonoids in order to help block harmful UV radiation, flavonoids remain woefully uninvestigated. What we do know is that they add to the flavor and scent profile of the flower, and help it attract pollinators and dispel predators. Flavonoids are high in anti-inflammatory and antioxidant properties, making them desirable for wellness minded cultivators.

There are 20 varieties of flavonoids that add ranges of color, from yellow to purple. Anthocyanin is a notable flavonoid for its presence in the leaf even at small amounts can color cannabis with the deepest of purple hues. Not only is it in the flower, but it can crawl up the trichomes, and add to the profile of the plant.

ACCESSORY PIGMENTS AND LED

Most plants are green because 70% of a plant’s pigment is chlorophyll. Chlorophyll can mask other plant pigments by outnumbering them, but when exposed to a full spectrum of light, plants respond by producing more accessory pigments.

This in turn, not only makes the plant more colorful, but it also helps the plant absorb more light. Because chlorophyll is so prominent, green light is reflected off and away, but plants rich in accessory pigments can absorb that light and use it in photosynthesis. In fact, under full spectrum LED grow lights, Cannabis plants produce more secondary pigments than plants grown under HPS lights

These pigments do wonders helping the plant harness more light, produce photosynthesis at a higher rate, and eventually grow and flower in a healthier and more colorful way. They’re also helpful in protecting the plant from stressors, like harmful radiation. These stressors can be detrimental to the quality of cannabis, and cause the loss of the stuff that gives cannabis its potency; the trichomes.

ON THE PLANT
TRICHOMES

In cannabis, trichomes serve a similar function as accessory pigments. These small, mushroom shaped crystalline structures are another way plants defend themselves from harmful radiation and predators. Trichomes deter animals with their bitter taste and strong smells, the very features consumers often look for when purchasing cannabis. Inside the trichomes, cannabinoids, terpenes and even flavonoids are stored, so the presence of more trichomes will often denote a more potent and nuanced effect.

Terpenes

Terpenes are naturally occurring chemicals that help form the trichome, and often are responsible for a strain’s aroma and taste. Some studies have investigated their effects on humans, and have postulated that there’s an “entourage effect”, where terpenes and flavonoids work in conjunction with cannabinoids in order to produce specific medical benefits by traveling through endocannabinoid receptors in the brain. Basically, terpenes and flavonoids hitch a ride through the endocannabinoid system within our bodies in order to produce more diverse and well rounded effects not only psychologically but also physically. The combination has helped in pain management (Johnson et al., 2010), analgesia (Gallily et al., 2015), cancer (Blasco-Benito et al., 2018), and even severe epilepsy. 

Cannabinoids

Cannabinoids are distinct secondary metabolites, and are formed in the trichome when a terpene and a phenol component combine. These chemical compounds give cannabis its potency and psychoactive effects. Tetrahydrocannabinol, or THC, is the much sought after cannabinoid popular for its ability to alter perception, however, along with CBD, it has been shown to have analgesic qualities and even anticancer properties.

TRICHOMES AND LED

Trichomes are very delicate. When exposed to stressful factors like high or low temperatures, or strong winds, the trichomes can fall off, the essential oils within them can degrade, and the overall quality of the plant will suffer. Because of the high heat of HPS lighting, trichome production and cultivation can be severely stunted.

Under LED grow lights, Trichomes form more regularly, especially at higher light intensity. Studies have shown that cannabis potency is increased when exposed to full-spectrum light provided by LEDs. What’s more, cannabis under high-intensity LED performs photosynthesis at higher rates than previously imagined. Cannabis lacks what scientists refer to as a saturating yield response. This is the point at which you stop seeing more results from increased light intensity.

In most plants, as they grow, they will require more light until they reach a certain point at which more light won’t improve anything. At this point, the plant will plateau in its growth and production. Cannabis has no plateau. As it grows, it can take increasing amounts of light, and when it reaches maturity, the more intense lighting you give it, the better it will do. Under high-intensity lighting, cannabis not only grows faster and heartier, it grows more trichomes, filled with diverse terpenes, flavonoids, and cannabinoids.<br />