Beginner's Guide to Growing CBD Hemp

As we enter into the first month of 2019, many are eager to start planning for the growing season. We've been fortunate enough to be in contact with many current growers and would like to pass along some fundamental knowledge learned in 2018 to future WI hemp growers. The majority of information online regarding hemp is directed towards 'hemp for fiber' growing. Here, we look at growing hemp for CBD production which is akin to traditional cannabis growing. Each topic listed below should be reviewed, scrutinized, and challenged as necessary. This is by no means an extensive bible, rather a brief overview of the things that should be considered before growing.

Administrative - To legally grow hemp in WI you need to apply for an Industrial Hemp Grower License through the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) which can be found here. 

Soil - Soil should have a pH between 7.0 and 7.4 (slightly alkaline). Organic or untreated soil is best. ZERO pesticides/insecticides/fungicides should be used when growing for CBD. The plant takes in the chemicals which ultimately gets concentrated in the processed oil (this is also why hemp is effective for removing toxins from soil).

Seed - Seed must be on the DATCP approved seed list to be legally grown in WI. Your seed genetics are the greatest influencer of your end product. You can turn high-quality seeds into a worthless product with negligence, but it is impossible to turn low-quality seeds into a valuable product. Seeds can be "feminized" meaning the majority of male seeds are removed. This limits the number of undesired male plants that need to be removed in the 'Growing' phase. Another option is to plant seedlings. These are typically clones of an already identified female plant called a "mother." This ensures that all seedlings are females and genetically identical. The seed vs. seedling debate is outside the scope of this brief overview but is worth examing closer. We highly recommend Oregon CBD.*

Planting - Planting dates varied between early June to late July for most growers. This depends on the weather and seed type. Plants should be spaced 4 to 6 feet on center. This means the center of one plant is no closer than 4 feet to the center of another. Plant about 0.5" deep. One seed/seedling per spot. 5 feet on center equates to roughly 1700 plants per acre. Many growers hand planted seeds in 2018, but some creative people are looking to modify existing equipment to automate this part. Placing a tarp with drip irrigation attached can save you many hours weeding/watering in the 'Growing' phase. Some growers enclosed their fields with electric or normal fencing to deter interested wildlife. The first thing most first-time hemp growers would tell you is that it was more work than they had expected, so we highly recommend starting small before planting multiple acres.

Growing - For CBD production, removing any male plants as soon as they are identified is of utmost importance. Removing males ensures that the female plants remain unpollinated and continue producing cannabinoids. Minimally stressed plants yield more (just like humans!). Minimize stress on your plants by watering during droughts and keeping an eye out for insects/wildlife interested in your hemp. Organic fertilizers can be used to boost growth, but many of our growers had massive plants with no fertilizers whatsoever. Again, no pesticides/insecticides/fungicides should be used to grow. Neem oil is often suggested as a "natural" way to control pests, but this is ultimately concentrated into the oil and causes uncontrollable vomiting and should be avoided. 

Harvesting - Before harvest, you must contact DATCP to schedule them to come and test your plants for compliance (i.e. they test below 0.3% THC). Harvest is ideally when your plants have the highest CBD content while still being below the 0.3% THC limit. This is, of course, very difficult to plan for. Most growers will just wait a certain amount of days, however, the savvy grower would use analytics (see here) to track cannabinoid levels and continuously monitor plants around the target harvest. Plants are typically hand harvested by cutting at the root and transferred to a proper drying location. Yes, this is a lot of work. It may be difficult to harvest all in one day or all in one week. Some found it a good idea to stager their planting, so their harvest was also staggered.  

Drying - A vital step in delivering a valuable product. Plants not properly dried end up moldy. Moldy plants are worthless to (most) processors and other end consumers. Please do not neglect the importance of your post-harvest duties. Plants should be hung upside down on ropes/stakes (similar to tobacco) in a cool, dark place with good air circulation. Ideal conditions would be no light, 60°F, 50-60% humidity for 2-3 weeks or till 8-10% moisture content in the plants (this is about when smaller stalks/stems snap instead of bend). Fans can help to prevent stale air, but should not be overused. "Cold and Slow" is the motto. Clean barns, sheds, or other enclosed environments appeared to be the most common 2018 drying spots. Popup tents could be used in a pinch for a minimal investment.

Trimming - Various trimming techniques are used depending upon the end product you wish to produce. The most valuable product is something akin to traditional cannabis found in dispensaries. From a processors perspective, this level of trimming isn't quite necessary, but the more leaves/stems removed, the more valuable the material (it will also increase your CBD levels). Cutting away large stems and leaves by hand, followed by a Twister Trimmer produces a satisfactory product. Below is an example of a satisfactory final product for our purposes.


Curing - Curing is the often overlooked last step of hemp growing. It ensures the product is dried thoroughly and can increase cannabinoid content. See the details of curing here. Note: the article only mentions increasing potency of THC, but CBD levels will rise as well. 

Further Reading: DATCP Industrial Hemp Pilot Program home page, Planting Guide from Oregon CBD Seeds (*highly recommend*).

January 10, 2019 Update: I also wanted to touch on expected yields. Of course, every plant under different conditions will produce a different amount of flower, but generally speaking, 1 pound of flower can be expected per plant. For conservative estimates, use 1/2 pound per plant. For those interested in toll processing, you can expect roughly a 10% overall yield for 10%+ CBD material. That is, for every 100 pounds of material processed, 10 pounds of oil will be made. This is again, is dependent upon the quality of material given to us.  Please drop a comment to share your growing experience from 2018 or your hopes for 2019. Best of luck to everyone in 2019! *Oregon CBD Seed has a 5000 seed minimum order listed. They recently changed the minimum to 1000 but have yet to update their website.