Farming Hemp for CBD Production
Most farmers have a plethora of questions when it comes to growing hemp for CBD production. With the implementation of the Farm Bill in late 2018, it’s evident that the consumption of cannabis derivatives like CBD is bound to hit skyrocketing levels.
However, that projection can't be realized when there is a limited production of CBD. To meet the increasing demand for CBD, having high-quality hemp genetics grown from seed will be crucial. There needs to be full consideration of all the different factors from sowing seeds to managing plant growth, harvesting and product preparation.
In this article, we’re going to cover everything about how you can grow hemp to produce the maximum amount of CBD for your effort. We’ll mostly focus on the commercial aspects of hemp, but much of this information will also be useful to people who want to cultivate hemp at home. Hemp and CBD are becoming competitive industries, so having the right strategy to help you succeed is more essential than ever. If you don't believe it, just check out the chart below showing the explosive rise of popularity in CBD, even compared to the popularity of cannabis and THC. This industry is expanding incredibly rapidly and knowing all facets of how this plant is grown and processed will help you be a better producer and consumer of hemp and CBD products.
What is Hemp?
mp consists of many varieties of cannabis that all have low levels of THC (legally defined as below 0.3%), which essentially guarantees the plants will have minimal psychoactive properties. Just to be clear, hemp is not a different species or a subspecies of cannabis. This is because they can be interbred and produce viable offspring, which is the biological definition of what separates species.
In contrast to typical medical cannabis varieties, most hemp varieties have been bred to have large and thick stalks that are rich in fiber, or to produce large flowers with many seeds that can be used for seed oil production. Hemp varieties also typically have lower total cannabinoid and terpene content than medical cannabis strains, except for some molecules such as CBD. This is why many hemp and cannabis growers have started hybridizing different varieties in recent years. Hybrids of hemp and cannabis varieties can be bred to obtain plants that have high overall flower resin (cannabinoids and terpenes) content and produce CBD as the dominant cannabinoid, instead of THC.
Most varieties of hemp, particularly the ones that produce high levels of CBD, are dioecious (meaning they have separate male and female individuals). Plants typically begin showing signs of sex/gender around the age of 8-10 weeks old, or when they are forced to enter the flowering stage by reducing the amount of light exposure over a 24 hour period. This can be a problem if farmers aren’t able to accurately identify male plants as they enter flowering stages. A male plant won’t produce resinous flowers, instead it will pollinate nearby females and cause them to produce less flower resin in exchange for seeds. If you’re intending to grow for CBD, this can be disastrous.
Female hemp plants are relatively easy to grow when subjected to the right conditions. These plants don't consume a lot of water compared to some other crops, which is good news for commercial farms. To grow the biggest and highest CBD producing plants, you’ll want to provide a nitrogen-rich medium for the vegetative stages and a more potassium and phosphorous-rich environment for the flowering stages. Achieving a successful nutrient regime can be accomplished in a variety of ways depending on how you plan to grow. Which brings us to the next point – should you grow outdoor our in a greenhouse?
The advantages and disadvantages of growing hemp in a greenhouse or outdoors is a complicated topic. It can simply depend on differences in local regulations, resource availability or personal preference. However, most often hemp that is grown in a greenhouse can yield denser flowers that produce higher percentages of CBD, which is made in resin glands called trichomes. Greenhouse farming also typically has greater water efficiency compared to outdoor farming, but the energy costs are typically higher due to use of supplemental lighting and environmental controls.
On the contrary, if low-cost land and water are readily available you may want to opt for a multi-acre outdoor field that can be more easily managed with large farming equipment. There are many more considerations to take into account when designing an industrial hemp production facility, so consulting with an expert before investing in any large endeavour is always recommended.
Conditions Necessary for Growing Hemp
Hemp naturally grows over most climatic conditions but doesn’t do well in mountainous or arid environments. The climate ought to be balanced – neither too cold nor extremely hot.
Hemp does well with:
When planting and growing hemp seeds they should be immersed and covered in the soil. Transplanting should only be done a minimal amount of times to most effectively manage your entire growing operation. Transplanting shocks your plants, so doing it too often will slow growth and lower your yields. Instead, try to only transplant a maximum of once, when moving the seedlings from the early vegetative stage to their final rooting location. Transplanting once still allows you to keep young plants in small pots that can easily be moved around and cared for; then, after determining each plants sex it can be moved to a larger container or the ground where the roots will grow freely for the remainder of the plants life.
Is Farming Hemp for CBD Profitable?
Common Concerns Among Hemp Farmers
Getting high-quality seeds can be a potentially difficult task when it comes to growing hemp for CBD production. As we mentioned above, hemp and hemp products must contain less than 0.3% THC to maintain compliance with U.S. Federal regulations. Finding a hemp variety that consistently produces these low levels of THC in your growing environment, produces high percentages of CBD, has robust growth traits and is mold resistant, etc. can be a trial-and-error process that requires testing different varieties in different growing methods. Most states in the US that are regulating industrial hemp programs have been issuing lists of certified varieties that should be compliant when grown in local conditions. Talking with experienced hemp farmers and cultivation consultants can help you properly select which varieties will work best for you.
Secondly, differentiating between male and female hemp plants can be one of the most time and resource consuming tasks to do - with severe consequences if not done properly. This is especially true when a grower wants to harvest hemp for CBD production because roughly half of all non-feminized seeds are going to be male. Waiting up to two months to identify plant gender can limit the overall productivity of a farm by not maximizing space and time used to maintain desirable female plants. Further, waiting to visually inspect plants actively costs resources such as water, electricity, labor, nutrients and pest control. Using a DNA testing service like Delta Leaf can eliminate the worry about identifying male plants and make growing hemp from seed more efficient than other methods.
Lastly, now that growing hemp is legal across the US, there can sometimes be stiff competition when it comes to selling the final CBD products. However, this is a rare case as the demand to consume CBD-related products from hemp has been nothing but exploding. Whether you decide to sell your harvested hemp flower to a specialized product manufacturer or embark on your own extraction and product development journey, it's still early and a great time to join the industry.
In closing, CBD is a popular new supplement that is getting huge attention across the world. Getting ahead of the curve is never easy, but there will clearly be many unforeseen opportunities in the hemp and CBD industry for the pioneers who are clever enough to figure it out. Feel free to reach out to us here at Delta Leaf if you think we might be able to help you get started on your own hemp growing venture.
How to do an F1 Cross
Suppose you have an awesome strain, and you want to make a high CBD version. Here’s the traditional way of doing it.
First, you want to make sure your strain doesn’t already produce CBD. You also need to find a male plant from a strain that makes lots of CBD. You can get males by growing a few plants from seeds. Next, you breed these two strains in what’s known as an F1 cross. Let’s draw a Punnett square to diagram how different versions of a single gene are exchanged during an F1 cross. It looks like this:
How to do an F2 Cross
Identifying High CBD and High THC Plants
At Delta Leaf we can identify whether a plant contains the Bt allele, the Bd allele, or both. This saves time and money by identifying the plants you want immediately after germination, instead of waiting months to observe the phenotype. We can also identify whether a plant carries the male, or “Y”, chromosome. Sample collection kits are available here on our website.
Below is a final summary graphic showing the entire process of breeding a high CBD strain. Thanks for reading and good luck with your breeding!
How Are THC and CBD Made?
Determining Levels of THC and CBD
When a male plant pollinates a female plant to make seeds, those seeds get one copy of each gene from mom and one copy of each gene from dad. If a plant has two copies of the Bt allele , then the plant will basically only produce THC. Likewise, if the plant has two copies of the Bd allele then the plant will only make CBD. However, if the plant has one copy of the Bt allele and one copy of the Bd allele, then it will have a mix of THC and CBD.
This is why most strains have either high THC, high CBD, or something close to a even ratio with neither cannabinoid becoming much higher than 15% dry weight. If you're growing cannabis or hemp from seeds, especially if you're considering doing any breeding projects, this information is essential to set the foundation for the work you'll be doing. Check out the image below to get an idea of what the different combinations of THC (Bt) and CBD (Bd) alleles look like at the genetic level.
At Delta Leaf we can identify whether a plant contains the Bt allele, the Bd allele, or both. This saves time and money by identifying the plants you want immediately after germination, instead of waiting months to observe the phenotype. We can also conduct gender identity tests to analyze male vs. female cannabis and hemp plants through detection of the Y-chromosome. Sample collection kits are available here on our website. Please contact us ahead of time if you want to get your plants tested for the Bt or Bd allele so we can discuss the specific requirements of your project.
How To Start Growing Cannabis
When the time comes to start a new batch of plants, there are essentially two main methods a grower can choose. The most common method is to make clones, or genetically identical copies of a “mother” plant. Cloning involves cutting off a piece of stem with some leaves, then planting it under conditions which make the stem grow roots and eventually a whole new plant. The second method, using seeds, is probably what people typically think of when growing plants. That’s because you can buy packs of seeds for vegetables or almost any other plant at the grocery store. Almost all major crops are grown from seed, and for good reasons. Modern agriculture has benefited from years of science that enables breeders to produce consistent batches of seeds; however, cannabis breeders haven’t had those same tools available, until very recently. An example of a technology that helps breeders speed up development of new strains is DNA testing, like what we offer here at Delta Leaf.
Advantages of Seeds and Clones
Compared to clones made using traditional methods, seeds produce plants that grow larger and are more disease resistant. Growing from seed also eliminates the risk of transferring "stowaway" pests such as mildew and gnats, which can show their face and cripple your garden after months of work. Plants grown from seed are reported to be heartier and larger because they establish what's called a taproot, which is the large central root that pokes out of a seed when it first germinates. The taproot grows straight down, anchoring the plant and sprouting all the lateral roots that extend outward. While clones might seem to save time because they're bigger when they enter your garden, it's not hard to plan ahead so that you have seedlings ready of similar size when you would normally buy or start new clones for your next grow cycle. When proper planning is used, seeds can easily replace clones in grow operations with high turnover (frequent harvests). Using Plant DNA Sex Testing also drastically improves the cost-efficiency of growing from seed.
Plants that are started from seed have also been reported to produce a larger harvest than clones that are started at a comparable stage. Finally, the most important aspect of plant health that is affected by cloning is the acceleration of senescence (deterioration due to aging). Each time a clone is cut from a mother plant, it creates a minor stress of infection and tissue damage that accumulates negative consequences over time. Worse, if a clone is taken from a clone (which must be done after a mother becomes exhausted), then senescence will only be accelerated further each generation you get away from the original seed. The multitude of advantages that seeds offer regarding plant health and vigor make them invaluable to many growers.
Seeds vs. Tissue Culture
Many of the disadvantages inherent to clone growing can be overcome using plant tissue culture, however, this requires costly infrastructure and continuous maintenance of culture stocks. Cannabis plants grow very rapidly and a single plant is able to produce thousands of seeds. These factors diminish the potential commercial benefits of using tissue culture (a.k.a. micropropagation) to supply clone stocks. Further, seeds are stable for long periods of time under a wide variety of environmental conditions and are easily germinated with high success rates. An individual seed also requires less space to store it than a micro-propagated plant. When consistent genetics become available as seed stock, the cannabis industry will no longer be reliant on clones to produce a consistent product. The hemp industry is already far ahead in terms of breeding certified varieties as well as being dominated primarily by seed growers. Both of these methods (seed production and tissue culture) can produce disease-free and genetically predictable starting points; therefore, overhead costs of maintaining seed stocks vs. maintaining tissue culture stocks will become the major factor in determining how cannabis genetics are propagated in the future - and the clear winner is seeds.
Below is a list of reputable seed banks you can purchase seeds from. This is not an endorsement for any of the following sites. Always check your local laws surrounding cannabis before purchasing seeds online.
For more information about the differences between seeds and clones, check out these other great articles:
1. Daniel Zohary, “Unconscious Selection And The Evolution Of Domesticated Plants,” Economic Botany 58, No. 1 (January 1, 2004): 5–10
2. Doyle Mckey Et Al., “The Evolutionary Ecology Of Clonally Propagated Domesticated Plants,” New Phytologist 186, No. 2 (April 1, 2010): 318–32
3. Mohan P. A. Marimuthu Et Al., “Synthetic Clonal Reproduction Through Seeds,” Science 331, No. 6019 (February 18, 2011): 876–876
4. Rachel S. Meyer, Ashley E. Duval, And Helen R. Jensen, “Patterns And Processes In Crop Domestication: An Historical Review And Quantitative Analysis Of 203 Global Food Crops,” New Phytologist 196, No. 1 (October 1, 2012): 29–48
5. Rachel S. Meyer And Michael D. Purugganan, “Evolution Of Crop Species: Genetics Of Domestication And Diversification,” Nature Reviews Genetics 14 (November 18, 2013): 840.
6. Trevor A. Thorpe, “History Of Plant Tissue Culture,” Molecular Biotechnology 37, No. 2 (October 2007): 169–80