Looking for a more potent harvest this time around?
Whether you want to grow cannabis that has a more psychoactive effect or you want to kick up your weed’s medicinal capabilities, it is possible to manipulate your plants to create more THC.
First, you need to understand how THC is produced.
THC is a specialized chemical that is only produced by cannabis plants. this chemical is a natural filter of UVB which can damage the plant’s ability to reproduce. THC is generated by the plant to coat the trichomes in the late stages of flower. THC is present only in female pants and only around the flowers and adjacent leaves.
Many strains of cannabis do not produce THC – these are called hemp and have not evolved the protection against UVB as the areas they originate from did not have high levels of THC.
THC is found in resin and oil produced by trichomes. And trichomes are the little, waxy, hair-looking resin glands you see on the surfaces of your cannabis plant. The more trichomes your plant produces and the more resin those trichomes make, the likelier you are to get the THC content you’re after.
There are a few ways to inspire trichome and resin production, including some clever manipulation of the lighting and environment. Here are a few tips to try for your next growth cycle.
Choose a Potent Strain
The genetics of your cannabis plant play a significant role in the potential for THC production. Each strain has a maximum potential for THC content. For example, the super popular Girl Scout Cookies strain can reach an astounding THC content of up to 28%, but that’s where it maxes out.
Whatever strain you’re growing, you should know there is a ceiling for THC content. If your plant’s genetics don’t allow for higher than 18%, you’re not going to achieve more than 18%.
However, you can very easily fail to achieve that max content, and plenty of home growers do. It’s expected. Growing cannabis is a learning process, and with each cycle, you get better and discover more tricks for yielding dense, sticky buds. Tricks such as . . .
Crank Up the Blue, White, and UVB Lights
When you have control over the light spectrum of your grow lights, you have the ability to tell your plants how to grow, how to flower, and how much resin to produce. This is why we highly recommend using LED light. Grow lights like these give you variable spectrum control, versus the old-school method of just switching out an MH (blueish) bulb for an HPS (reddish) bulb.
In order to get more THC in the flowering stage, you want to inspire your plant to produce more resin-producing trichomes. You do this by cranking up blue, white, and UVB lights to 100% and backing red down to around 50%.
Why does that work?
Cannabis plants produce trichomes protectively. In nature, these little guys use trichomes and the resulting resin as a sort of buffer against the sun’s UVB rays. The better you can mimic that light in your grow room, the more trichomes you’ll get and the better shot you’ll have at reaching maximum THC content.
Cannabis plants have a built-in sensor for the UVB level in the light. Higher levels of UVB in the light will trigger higher levels of THC which will coat the trichomes as a protective filter.
Using a supplemental UVB light in the later stages of flowering will increase THC levels.
Let Your Plants Get a Little Dry
You want to be delicate with this next tip. Try it, but also keep an eye on your plants so you don’t overdo it.
Let your cannabis get a little thirsty. Not parched. Not shriveled. Just remove a little bit of moisture from their lives. If you can reduce the humidity in your grow room, that’s the perfect move.
Just as they do with UVB rays, cannabis plants protect themselves from dry climates by producing more resin. You know you’d never let them die of thirst. But as long as they don’t know that, their protective instincts will mean more THC for you.
Optimize Temperature for THC Production
If you’re starting to feel bad about manipulating your plants into defensive mode, here’s a gentle approach. As your plants enter the flowering stage, decrease the temperature of your grow room by about 10-15 degrees.
This slight change in temperature tells your plants that autumn has arrived . . . which means they need to hurry up and flower for the sake of their species. As a result, your plants put all their energy towards resin production.
The Best Time to Harvest for Maximum Potency
Timing is everything. There’s no point in having succeeded at all of the above if you miss the sticky-bud harvest window. There are about 2-3 weeks during the flowering stage when you can harvest your cannabis at peak maturity. You’ll know you’re at this stage because the trichomes will have turned milky white. Another reliable indicator is that the pistils (those little white hairs on the buds) will be darker and curled inward.
This is when your plant is in its prime and the THC level is the highest it’s going to be this grow cycle. Harvest, see if you can tell the difference, take some notes, and start the next cycle. For a lot of home growers, getting the chemical profile you want requires some patience and trial and error. Frankly, that’s part of the fun.
That said, if you want to take some of the guesswork out of the process, our LED grow lights can help you make huge strides toward reaching your goals. And if you have any questions for us, we’re always excited to help new growers find their footing.