The Definitive Guide to Growing High CBD Marijuana Strains
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.
Unfortunately, it is surprisingly hard to find high-CBD cannabis strains. To grow them is even harder. Here are a few quick tips to get you started.
Is Growing High-CBD Cannabis Different from Growing High-THC Cannabis?
If you’re thinking about growing hemp or high-CBD strains of cannabis in order to harvest the CBD, you may be wondering how similar the process is to growing cannabis for THC.
The process is remarkably similar, but not exactly the same.
On a biological and legal level, the only difference between hemp and high-CBD or high-THC cannabis plants is… the amount of THC and CBD. These are all simply different strains of the cannabis plant.
This plant in the front is a high-CBD strain of cannabis, with low levels of THC. Those plants in the back? They are all high-THC strains of cannabis. It’s hard to tell the difference, isn’t it? That’s because the only difference is the THC percentage.
Closeup of a bud on that same Critical+ CBD Auto plant
Hemp vs Cannabis vs Medical Marijuana: Like Different Strains of Roses
I look at my balcony and I have two rose bushes; a “Floribunda” and a “Fragrant Cloud”. They’re both strains of roses, but they grow differently and their flowers look and smell markedly different. The Floribunda grows lots of tiny orange roses that don’t have much of a smell, while the Fragrant Cloud makes just a few big hefty red roses that envelop the air with flowery perfume.
Each of these roses has their own “personality” but the actual plant care is basically the same. They get the same types of nutrients, watering, pruning, etc. This is basically what you’re looking at when it comes to different strains of cannabis, hemp or marijuana.
What is hemp and why is it legal?
Hemp was recently legalized on a federal level in the United States. But how is hemp different from cannabis?
There is exactly ONE difference between regular cannabis or marijuana and hemp….
The THC content. That’s it. You can have two strains of cannabis that look exactly the same, but if one contains less than 0.3% THC, it is considered hemp, while if it has even 0.4% THC by dry weight (in any part of the plant) it’s no longer considered to be hemp.
Learn more on the USDA government website (Excerpt: “The term ‘industrial hemp’ includes the plant Cannabis sativa L. and any part or derivative of the plant including seeds, whether or not it is used exclusively for industrial purposes (fiber and seed). The tetrahydrocannabinols (THC) concentration is the distinguishing factor between industrial hemp and marijuana. Industrial hemp cannot have a THC concentration more than 0.3 percent on a dry weight basis.”)
I know it seems like it should be more complicated than that, but that’s it. “Industrial hemp” is basically any strain of cannabis with extremely low levels of THC. The strains of hemp used by farmers typically have also been bred for a specific purpose such as providing fiber.
These plants are a type of industrial hemp. This cannabis strain has been selected to produce negligible amounts of THC and strong fibrous stalks.
How to Grow Cannabis or Hemp for CBD
If you want to grow your own CBD, the most important thing is to start with a high-CBD strain. You can’t force a cannabis plant to produce more CBD than its genes allow, and many if not most popular cannabis strains contain high levels of THC and less than 1% CBD. Genetics is key!
- Choose a high-CBD strain of cannabis.Note: if a plant contains more than 0.3% THC it is not considered hemp. If you’re concerned with THC percentages and making sure you’re growing hemp, it’s extremely important to get a strain from a trusted breeder.
- Grow mostly like typical cannabis. Here’s a 10-step guide to getting set up and growing your own cannabis. Here are tips for increasing CBD when growing cannabis.
- Pay attention to harvest time. For the highest levels of CBD, you should harvest plants at the beginning of the harvest window. Both CBD and THC start to degrade as buds continue to mature. If you harvest buds late there are a few differences. Buds harvested on the later side usually have slightly lower levels of CBD and THC, but higher levels of CBN. As a result, buds harvested later tend to be less psychoactive (due to less THC), and are more likely to make you feel sleepy or have a strong body effect (due to more CBN). Because of the various ways cannabinoids interact with each other, it’s important to experiment with harvesting early vs later to see what works best for you. Just because harvesting early gives the absolute highest level of CBD doesn’t mean the resulting buds will work the best for you. You should experiment with different harvest times because every body reacts differently!
- Keep the leaves. CBD is contained not just in the flowers/buds of the plant, but also in the leaves. The CBD concentration is relatively low so the leaves are not suitable to smoke, but the CBD can be extracted by turning the leaves into things like butter, tincture or oil. Note: CBD extractions made from leaves are typically less concentrated/strong than extractions made from the actual flowers/buds.
- Extracting CBD. Unlike the leaves, the CBD-rich buds/flowers are often smoked or vaped. However, many people prefer to consume them in some type of edible form. This has a slower onset but the effects tend to be longer-lasting. For the most part, any method that extracts THC will also extract CBD, as they’re both cannabinoids that easily attach to oil. The problem is you can’t easily separate THC and CBD from each other. So if the starting plant matter has no THC, then a simple extraction into butter/oil/tincture will extract the CBD. But if you’re trying to get just CBD from plant matter that has both THC and CBD, well you need equipment for that! This is why it’s so important you start with the right strain. If the plant produces only the cannabinoids you want, you don’t have to do anything but extract and enjoy them.
We’re currently testing various methods to further increase CBD levels when growing small hemp plants indoors. We’re also collaborating with experts to produce the best butters, oils, tinctures and CBD-rich candies so you have access to professional quality CBD sources at home. Stay tuned!
Is Growing High-CBD Cannabis Different from Growing High-THC Cannabis? If you’re thinking about growing hemp or high-CBD strains of cannabis in order to harvest the CBD, you may be wondering how