Cannabidiol, better known as CBD, is typically the second most abundant ingredient in marijuana behind THC. While THC is renowned for providing users with a psychoactive high, CBD is non-intoxicating and could enjoy a more lenient legal status should the Hemp Farming Act of 2018 get passed into law.
Research into CBD is still ongoing, though scientists have identified at least 60 different molecular pathways through which it operates. It acts via various receptor-independent channels and binds to different receptors in the brain such as serotonin 5HT1A and TRPV1. More importantly, CBD is believed to be a powerful anti-anxiety and anti-inflammatory agent.
In a World Health Organization (WHO) report*, published in November 2017, there is a litany of research studies which seem to prove CBD’s therapeutic effects. Unlike THC, CBD does not seem to act directly on CB1 or CB2 receptors although it does act as an agonist with CB1 receptors.
Although CBD reduces heart rate and blood pressure when used on animals, tests have shown no such impact on humans under normal conditions. As it seems to be non-intoxicating, it has been approved for medical use on children, especially those with epilepsy and conditions such as Dravet Syndrome (Epidiolex is a recent FDA-approved CBD-medication to reduce the frequency and severity of seizures).
While it is already a burgeoning market, if the Hemp Farming Act is passed into law, one can expect the CBD market to explode. Given its purported medical benefits, coupled with the increased amount of information available on growing marijuana, it is not a surprise to learn that patients and commercial growers all over the country are trying to cultivate genetically bred high-CBD strains.
When you get it right, you can potentially save a small fortune by eliminating the need to buy expensive CBD oils and extracts. In this guide, we outline how to grow high CBD marijuana strains for personal use.
How to Grow High CBD Marijuana: It’s All About Genetics
There is no way to enable your cannabis plants to produce more CBD than is genetically possible. For example, there is nothing you can do to transform a high-THC strain such as Strawberry Cough into something like ACDC which has a 20:1 CBD to THC ratio.
In cannabis reproduction, weed grown from seed can express an array of different phenotypes unless it is a clone. In other words, two offspring from the same marijuana plant can have very different genetic features.
A prime example is if you try to grow a high-CBD plant from seed using Cannatonic, a strain with up to 12% CBD. Typically, your chance of successfully growing the high-CBD plant from a Cannatonic seed is below 75%.
United Seed Banks suggests that only 50% of Cannatonic plants grown from seed will contain its renowned 1:1 CBD to THC ratio. Approximately 25% will be high-THC plants, while the remaining 25% could have a CBD to THC ratio of anywhere from 2:1 to 20:1.
Aside from using clones from plants that have produced high-CBD strains, your other possible step is to talk to breeders about the phenotypes that could develop from their strains. It is beyond frustrating to sink weeks or even months into a crop of potential CBD-rich plants, only to discover that they are primarily THC-laden.
Growing High CBD Marijuana Requires Early Testing
If you elect to play the genetic lottery by growing high CBD marijuana from seed, make sure you get samples tested by a reputable lab while the plants are still young. Most experts agree that you should perform testing 3-4 weeks after the seedlings emerge from the soil. By doing this, you can identify CBD-rich plants long before they start to flower.
To perform this test, take a few of the plant’s top nodes as a sample. Make sure they are dried before submitting them to the lab. Through this process, you can identify CBD-rich plants and take cuttings from them for immediate growth to full-maturity.
If you’re unable to get your samples tested, you’ll have to wait until the flowering stage. At that point, your only real option is to consume some to determine whether it offers a psychoactive high or not. If you feel noticeably stoned, then the plants contain too much THC.
How the Growing Process Affects High CBD Marijuana Strains
While you can’t force a plant to produce more CBD than it is genetically capable of, you can coax it into producing the maximum possible amount.
In a 2011 study* by Sikora, Berenji, and Latkovic, researchers looked at six years’ worth of data on the growth of industrial hemp. They found that there were specific growing conditions associated with CBD-rich plants (though it is important to note that while the study was both lengthy and detailed, it only tested 20 samples).
Assuming you choose seeds with the right genetics, your next step is to ensure your plants are in soil that is warm approximately 5 cm down. Also, the more precipitation the hemp was exposed to in the 2011 study, the lower the CBD content. Overall, make sure your growing room temperature is between 68 and 70 degrees Fahrenheit, and when it comes to watering, err on the side of caution.
3 of the Best High CBD Strains to Grow Indoors
The main reason to focus on CBD-rich strains is for medicinal purposes. Also, be advised that you need to check your state’s laws before proceeding with any form of cultivation, as growing is still not permitted in all medically-legal states.
Also, although your electricity bill is likely to increase, the added expense is more than offset by what you’ll save by not having to purchase marijuana from a dispensary.
The amount of CBD produced by a plant ultimately varies according to the strain, lighting, and other factors. However, for argument’s sake, it is likely that you’ll grow a gram of usable weed per watt of light used. If you use a 400W HPS lamp, for example, you can produce up to 400 grams of usable marijuana, which equates to 14 ounces.
By way of example, if you live in Edgewater, Colorado, the cheapest ounce of Cannatonic you’re likely to get is $165. When you grow 14 ounces, you’ll have $2,310 worth of weed — and we guarantee that it costs you a LOT less to cultivate it!
In any case, here are three high-CBD marijuana strains that are ideal for home growers:
1 – CBD Blue Shark
This is a relatively mild strain which normally contains a 1:1 THC to CBD ratio and seldom has more than 7% of either cannabinoid. It is an indica-dominant hybrid (70%) that makes you feel mellow and is used by arthritis, fibromyalgia and Crohn’s disease patients. Its short flowering time of 65 days is great for indoor growers, and it produces up to 550 grams per square meter of flowers.
2 – CBD Critical Cure
This is another mellow high-CBD strain with a THC content of 7-11%, and an average CBD content of 7%. It is another indica-dominant hybrid (70%), and it offers a sleepy effect that helps numb physical pain. It is regularly used by patients for inflammation, chronic pain, and depression, and it can flower in as little as 55 days and yields up to 600 grams per square meter.
3 – CBD Kush
This is an evenly balanced hybrid which can have a 1:1 ratio, although some strains have just 1% THC against 7% CBD. It is popular with muscle spasms, chronic anxiety, and stress patients. It is ideal for a small setup as it only grows to around 60 cm in height. It takes approximately 70-75 days to flower and produces 400 grams per square meter.
Final Thoughts on Growing High-CBD Marijuana Strains at Home
The key to growing high-CBD marijuana strains at home is to identify a strain that’s likely to produce cannabidiol in larger (or equal) amounts as THC. Once you have been successful and identified a strain with appropriate genetics, make sure you use clones instead of seeds to avoid any guesswork in the future.
After choosing the right clones, grow the plants in a room with a relatively high temperature and resist the urge to overwater them. Ultimately, you will be able to grow high-quality medicinal marijuana and save a fortune compared to what you would pay for high-CBD marijuana or edibles from a local dispensary.