How to Increase THC in your Cannabis Plants?

09 February 2023
Find out how to grow buds with the highest THC in this article.
09 February 2023
16 min read
How to Increase THC in your Cannabis Plants?

Read more
  • 1. Why increase thc?
  • 2. How to increase thc
  • 2. a. Genetics
  • 2. b. Health
  • 2. c. Light
  • 2. d. Use training techniques
  • 2. e. Harvest at the right time
  • 3. How to increase cbd in your cannabis plants?
  • 3. a. Grow cbd strains
  • 3. b. How should i choose a cbd strain?
  • 3. c. How to maximize cbd?
  • 4. In conclusion

One of the main reasons you smoke cannabis is just that you get knocked out. Sure, there are medicinal cannabis users that prefer CBD, but for recreational users THC is king. There’s nothing more satisfying than smoking or ingesting cannabis that blows your mind. But, the caveat is that not all strains make you high. Cannabis users love that elusive THC that sends their creative minds thinking. And, cannabis growers are always looking for ways to increase THC. It’s not child’s play, but it can be done. So, today, we’ll teach you exactly how to increase THC in your cannabis plants.

The majority of recreational growers have sought out high levels of THC during the past few decades; it’s quite obvious why this has been the case. However, as cannabis science progressed, researchers have found that it’s much more than mere THC that contributes to the overall effects of each cannabis variety. Think about it, you can grow ten strains that feature a THC concentration of 20%, but that all produce varying subjective effects. Why is this? Because many of the phytochemical profiles of cannabis flowers work together to produce a unique high. Of course, THC creates the core psychoactive effects, but other phytochemicals add accents to each variety’s high.

These molecules include terpenes—the aromatic hydrocarbons that also contribute to the scent and taste of each strain. With that said, THC content also remains very important for recreational and medical users alike. Every time you visit a seed bank to purchase cannabis seeds, you’ll come across a data sheet that informs you of the expected THC content within the flowers you’re about to grow. But is this really the limit? In many cases, yes. But growers can take numerous steps in order to maximize the THC content of their finished product. So if you're looking to get a more potent effect out of your harvest by increasing your plant's THC production, read along to understand how to do it properly!

1. Why increase THC?

You’ll rarely find someone that doesn’t love some dank potent cannabis. Almost every recreational smoker loves THC – Tetrahydrocannabinol. The higher, the better. Whether you’re growing for personal or commercial purposes, everybody appreciates some hard-hitting cannabis.


How to increase thc: why do it?

Trichomes on a beautiful purple bud.

 As long as you don’t overdo it, THC can actually work wonders. Like CBD, THC also contains medicinal properties, reducing anxiety, easing headaches, reducing nausea, and also contains other benefits but that’s a topic for another post.

2. How to increase THC

Before starting you must know that there’s no way to increase the THC percentage; This is because cannabis strains have a limit and when growing in optimal conditions, you end up reaching that limit.

So for example, if you’re growing a strain that contains 25% THC in a top-quality grow space, it will be super hard to make it actually produce more trichomes but if you’re not growing in optimal conditions, there’s still room for improvement which can lead to an improved trichome production.

It’s essential that you have in mind that everything affects plant growth, from the temperature to the substrate, now, there isn’t a better substrate or nutrients; As long as you use them properly you can have the same results with any grow setup ut it’s super important that you provide good growing conditions, it doesn’t matter if you’re growing under an HPS, LED or even outdoors, you need to maintain good conditions.


How to increase thc: how to do it

There are several ways that can help you achieve a better trichome production.

This happens because, as said above, cannabis plants will grow to their maximum when growing in optimal conditions and in this case, will produce lots and lots of trichomes that contain not only the cannabinoids but also terpenes which are also responsible for the effect you experience when smoking a certain strain.

So if you’re growing with really good equipment, there’s not much you can do other than investing in good-quality genetics that will help you reach your goal but, if you’re a beginner grower and are just starting in the cannabis growing world, there are some minor adjustments and thins you should keep in mind to improve the overall harvest quality. If you were wondering how you would increase THC production, no, there’s no magic involved; It will all depend on your growing equipment and your ability as a grower because there are several ways to increase THC in the plants you grow at home. And, they include the following.

Related story
What is THC?


Do your homework before you purchase seeds. For instance, Gorilla Glue Auto is pretty famous to knock you down. Some tests reveal that it comes with a whopping 24% THC with low levels of CBD. That’s the kind of strain you should be looking for. Another strain that packs a punch is Girl Scout Cookies Auto. No matter what you choose, make sure you educate yourself about THC levels of the strains.


How to increase thc: genetics

Each strain has its own limit so make sure you start with a strain that allows you to achieve your goals.

As you can surmise, your quest to increase THC begins before you even purchase seeds. If you buy seeds that’s guaranteed to produce high amounts of THC, half of your work is done already. Keep in mind that the way you grow plants also determines the levels of THC. Beginners usually don’t get yields with high THC because you need experience, but if you continue without getting disappointed, you will be able to grow buds that are nothing but THC machines!

Girl Scout Cookies Auto
5 out of 5
there was a lot of back and forth but the guys stayed patient and polite throughout. helped a beginner like me resolve a lot of issues.
Verified customer
Reviewed 21 December 2022

Genetics play such an important role in THC levels, because they dictate the type and quantity of phytochemicals that a particular cultivar produces. This all has its roots in selective breeding over a period of time. During this process, breeders select and cross plants that already demonstrate high levels of THC, which often means that the progeny produces even more of the psychoactive cannabinoid.

Plant THC content all starts with a cannabinoid acid known as CBGA—also called the “mother cannabinoid”. Plants possess a variety of enzymes that dictate what CBGA becomes. Those higher in the enzyme THCA synthase naturally produce higher levels of THCA, the chemical precursor of THC. For example, as you can see, our Girl Scout Cookies already contains very high amounts of THC so by doing any of the things mentioned you can get a really potent effect.


Okay, now that you’ve bought some high-THC strains, what next? Well, the next thing is to pay attention to the health of the plant. It’s no secret that happy and healthy plants with amazing genetics produce high levels of THC. And, that’s what you should be focusing on.

But, how do you make sure that the plant is healthy? Firstly, you need to take care of the roots. Start by choosing good containers that help the roots breathe and branch out. Smart pots and airpots are perfect for this because they are designed to aerate the roots. Next, do not overwater. It’s okay if you don’t water too much, but cannabis plants with their feet wet constantly will either wilt and die or produce small yields with little to no THC.


Cannabis plants love loads of light. They just can’t do without it. Autoflowers, for instance, grow with even 12 hours of light but you will notice a huge difference if you provide 18 hours of light and 6 hours of darkness. Some growers go by the 24/0 light cycle but that’s not necessary. Like humans, plants need some rest and a lot of light will deter their progress!


How to increase thc: light

A good light fixture is the main thing you should look for if you want to increase trichome production.

There are so many varieties and types of lights available in the market today that you’ll be spoiled for choices. Read the manufacturer’s instructions and pay attention to the wattage of the light. Obviously, the more the wattage the stronger the light, but you should also purchase lights depending on the space you have.

Generally, the plants will be happy with about 40 to 50W of light per square feet. Keep this in mind before purchasing lights. If you have a small place, set up a lighting system accordingly. Additionally, make sure you set up lights that have UV light in them. Many LEDs have this option along with Infrared. Basically, cannabis plants produce high amounts of THC when they get ample light.

Use training techniques

The point of using training techniques is to stress the plant. But why would you stress the plant? Well, cannabis plants produce more THC when stressed. Generally, plants work harder when they get stressed. You can also reduce watering to stress the plant more. This way, it will produce a lot more trichomes.


How to increase thc: scrog

Scrogging allows all the flowering to get equal lighting, resulting in a better trichome production.

So, what are the best training techniques that stress the plant? You can start with topping or FIMming which will also work. When combined with LST, the plants will more produce so much resin that the leaves look like crystals studded with sugar (now you know why they are called sugar leaves).

While topping is a process where you cut off the top of the plant after it produces 2-3 sets of true leaves, FIMming also produces similar results. Not only will you help increase the number of colas, but the resin production will also increase.

When LST or Low-Stress Training is used along with topping, the results can be dramatic. LST, as the name suggests, is a training technique to stress the plant, but it doesn’t overdo it. It also ensures that all the parts of the plant get more light. By bending the tops of the plant towards the sides of the container, even popcorn buds at the bottom of the plant get more light.

Lemon AK Auto
5 out of 5
She was very easy. She grew quite chunky considering she's a sativa, but the effects did feel sativa. She has a lovely taste.
Verified customer
Reviewed 19 January 2020

It’s key to remember that you shouldn’t stress the plant too much. Doing so will not only hamper the growth but it also reduces THC. You can also decrease the humidity of the grow room so that it produces a lot more resin to protect itself from harsh environmental conditions. In the wild, cannabis plants produce more resin as a way to protect itself. If you apply the same logic while stressing the plants, it’s a guarantee that the plants will produce more THC.

Harvest at the right time

Cannabis plants produce a lot of THC if you actually harvest at the right time. To know when to harvest, take a close look at the trichomes of the plant. In the beginning, you’re going to have to look at the pistils. As the plant matures, the pistils that look clear at the beginning turn white and then proceed to become amber during the last stages.

When the pistils turn white, use a microscope to check out the trichomes at the same time. Many growers also use a jewelers loupe to do the same. Any microscope that can zoom from 30 to 100x will do the job just fine.


How to increase thc: harvest at the right time

It's essential you harvest at the right time for the ideal effect.

So, once you look at the trichomes, you’ll know whether they are clear or cloudy. Once they are clear, you’ll need to keep an eye on them every other day. As soon as the trichomes start to appear a little milky, it indicates that the plant has matured.

You need to check different bud sites because the tops usually mature much before the other parts of the plant. This is because the tops usually get a lot more light compared to the rest of the plant. This is also why you use training techniques like LST so that the light spreads in an uniform manner to all parts.

Once the trichomes look opaque or milky white, you can begin harvesting the plant. However, if you wait a lot longer the milkiness turns amber and the THC is broken down into CBN. If you see a majority of the trichomes turning opaque, it means THC is at its highest.

3. How to Increase CBD in Your Cannabis Plants?

If instead of THC you’re looking to increase CBD content in your plants, then it’s essential you know a couple of things. 

Grow CBD Strains

So first of all, you will need to start with CBD strains as this is the most important and effective way to maximize your plant's CBD production. Keep in mind that THC strains also produce CBD but at much lower concentrations, so make sure to look for medical cannabis strains or strains with higher CBD contents. 

How Should I Choose a CBD strain?

Well, first of all, is to find a trustworthy seed bank, so make sure to ask your friends where they get their seeds from or look at the reviews. Once you have chosen the seed bank is time to find the right seeds. So basically, you have three options, you can either grow Industrial hemp seeds which should contain less than 0.3% THC and high amounts of CBD, or if you cannot find hemp seeds, go for cannabis strains bred to produce high amounts of CBD.

CBD Auto 201
5 out of 5
I have grown this 3 times now and I always like the result. Each time it has grown slightly different, but I find the effect is always the same.
Verified customer
Reviewed 4 June 2020

Nowadays it’s fairly easy to find CBD-dominant strains dedicated to producing high amounts of CBD, which are the best choice if you cannot find industrial hemp seeds. Despite the high CBD content, industrial hemp seeds produce much smaller buds than regular cannabis seeds so if you’re wondering which one is the best, it depends on the consumption method. 

The third option would be autoflowers. Autoflowering cannabis seeds are a great choice as some autoflower varieties produce higher amounts of CBD when compared to photoperiods due to their genetics. As you may know, autoflowers contain Ruderalis genetics which naturally had a higher CBD content.

How to maximize CBD?

Now that you know the seed options available, let’s take a look at a couple of techniques that may help you increase CBD yields. First of all, it’s vital to keep your plants healthy, well-fed,  and disease-free as healthy plants will produce more THC and CBD. On top of that, it’s important to harvest your plants at the right time because if you harvest too early you will get a more Sativa-like effect, if you’re looking for a more medical effect, it’s super important you harvest when the majority of the trichomes have turned amber as with time, THC transforms into CBN, which is another cannabinoid similar to CBD. And, the last tip would be to adjust to the growing conditions. Studies on hemp cultivation have shown that warmer soil temperature, warmer air temperature, and dryer conditions can increase CBD production.

Related story
What is CBD?

4. In conclusion

You can apply all these methods to get more THC, but it’s important to choose strains that are already proven to produce more THC. Apart from the light fixture, genetics is one of the most important factors when talking about THC production.

If you're an experienced grower and have other tips and tricks to boost trichome production, feel free to leave a comment in the comment section below!