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Patrick McHugh is growing 20 acres of hemp for CBD at his farm outside La Crosse, Wis. Plants are spaced widely to reduce pressure from pests and diseases. Photo by Stephanie Coffman

Growing hemp for CBD presents opportunities, challenges for farmers

By Chuck Anderas, MOSES

Hemp is a wild new frontier for American farmers. Having only recently been legalized state by state in the last few years and nationally in the 2018 Farm Bill (still to come into effect), farmers, marketers, processers, and researchers are scrambling to figure out best practices and develop reliable supply chains. This is especially true for hemp harvested for cannabidiol (CBD).

CBD is one of the medicinal compounds in hemp, which is a form of cannabis sativa that is low in tetrahydrocannabinol (THC), the psychoactive compound in marijuana. While CBD has been getting a lot of attention for its pain-relieving properties, the Food and Drug Administration (FDA) cautions that dosing, drug interactions, and other questions about CBD use have yet to be answered. The FDA announced in May that “under current law, CBD and THC cannot lawfully be added to food or marketed as a dietary supplement.”

While CBD works its way through the federal arena, many states, including Wisconsin, are issuing licenses to grow industrial hemp and hemp for CBD. Patrick McHugh grew 40 acres of hemp for CBD this year on his certified organic farm outside Onalaska, Wis., which was a focal point at a field day this summer hosted by MOSES and OGRAIN. McHugh said he added hemp to his rotation “first and foremost for diversity, the ability to incorporate another crop in our rotation, positive health benefits, and the challenge.”

With production costs ranging from $5,000 to $10,000 per acre, it is important to know the risks of production and marketing before planting.

McHugh likened marketing CBD to marketing hay. “If I have high- quality hay, I have no trouble finding buyers,” he explained. “If I can produce a high-quality product people will be pounding on the doors.”

That being said, finding markets for hemp for CBD can be complicated. Since hemp is such a new crop, it does not have the infrastructure that established commodities, like corn, have. Farmers will have to be more proactive in their marketing than with typical grain crops. Jay Fentress with Higher Yields Consulting recommends that farmers do the work early to connect with people and look around for good prices.

If you sign a contract, make sure to look at it carefully. According to FL Morris and Steve Acheson of South Central WI Hemp Cooperative, there have been some bad actors in the hemp market. They have seen contracts written by companies backed by venture capital that put all the risk on the farmer. Morris said that “the narrative that you shouldn’t plant anything until you have a contract to sell it puts all the power in the processer’s hand.” Morris noted that contracts have sometimes used vague language like that they would pay “market value” for the crop at the end of the growing season without setting parameters for what “market value” could mean. Other contracts have the processor taking 40-60% of the biomass as payment for processing the rest.

Joe Rivas of Rivas International is building brands of CBD for treating PTSD for veterans. He said that contracts are inappropriate in states like Wisconsin where farmers are in their first or second year of growing the crop. Rivas plans to have contracts with growers once they have a track record and have built relationships.

The farmers I spoke to for this story said that it is best to make lots of phone calls and get acquainted with buyers early. Don’t take the first contract offered to you, but keep asking around and compare what is offered by each company. Because of the seductive promise of huge profits, the industry has attracted people who might not have the best interests of the farmer in mind. Be cautious and seek arrangements that share the risk between all parties.

Morris and Acheson formed South Central WI Hemp Cooperative in February 2019 in response to both market and production challenges. To Morris and Acheson, organizing farmers in a cooperative was the only way to form a hemp industry that works for farmers instead of the larger industry and investors. Acheson said they didn’t want to see hemp “turn out like every other agricultural industry where there is an oversupply, and then the farmer gets a rock-bottom price, and the only way to survive is to produce huge amounts of crop. We want to flip that on its head and give the power to the farmer.”

With the help of the Center for Cooperatives at the University of Wisconsin, Acheson, Morris, and a small group of local farmers organized their co-op. They have done group buys (available to non-members) for seed, fertilizer, and irrigation equipment. Buying seed together has helped them access genetics that would not have been available to them as individual growers because of large minimum purchase requirements. Co-op members have an internal forum to support each other as production issues arise, often giving each other advance warning of pest pressure. The co-op plans to market their product together to have more negotiating power than they would as individuals. They are also making plans to help members build hoop houses and a cooperative drying facility.

Along with the legal and marketing challenges with CBD, farmers and researchers alike are working to find the best agronomic practices for producing hemp for CBD.

“After 70 plus years of prohibition, everything is pretty new,” said Ashley Walsh of Pocono Organics. “Lots of knowledge has been lost; so, we’re starting from scratch again.”

The prohibition also applied to research, so there is little scientific data on the best cultivars, planting dates, spacing, nutrient requirements, pest management, and other agronomic issues for Midwest growers. When there is data, it is usually from states and countries where cannabis has been legal for longer, and it is unclear how that information will translate to our climate and soils.

Hemp for CBD can either be transplanted or direct-seeded. Producers start with feminized seed or female transplants because female flowers produce significantly higher quantities of cannabinoids than male flowers. To direct-seed, many farmers have used a corn planter with a sorghum plate. Transplanting hemp is no different from transplanting any other crop and can be aided by vegetable production equipment like water wheel transplanters. It is commonly either transplanted into plasticulture or a living cover of clover, tillage radish, alfalfa, rye, or a mix of these and other crops that are mowed throughout the season.

Hemp grown for CBD needs to be pinched back or topped to encourage multiple flowers. Photo by Stephanie Coffman

Spacing depends on a number of factors, but some data shows that yields per acre are highest at the tighter spacing of one foot by one foot. However, there does not appear to be any data comparing cost per acre and yields at different spacings. It seems that most farmers are planting CBD hemp at a wider spacing of around 4- to 6-square feet apart. Because the cheapest feminized seed costs over $1 per seed, farmers may choose to grow at a wider spacing to limit the cost of production. Wider spacing also increases airflow around the plants to limit mold and other disease issues.

Starting with feminized seed does not guarantee there won’t be male flowers in a field. Producers are scouting their fields regularly to remove male flowers.

McHugh started his first transplants mid-May, transplanting every week, and switched to direct-seeding at a tighter spacing later in the season. This helped stagger the workload for both planting and harvesting, and could help make the most of limited space for drying the crop.

Most varieties that are available were bred in the drier climates of Colorado, Oregon, and California, and it is unclear which varieties will work best in the more humid Midwest. Dr. Leah Sandler, the education director and research agronomist at Michael Fields Agricultural Institute, is conducting cultivar research to see which of the 10 they are studying will work best in Wisconsin. She is also organizing a grower survey to learn which varieties worked best for them. In 2019, it seems like farmers had to take whatever they could get of a reasonable quality at a reasonable price. With each year that passes farmers will have better information on which cultivars to grow for CBD production.

A common misconception is that hemp can grow anywhere. Instead, hemp should be grown on good, well-drained soils, and fertility should be closely managed. Overall health of the crop is the main way that farmers can grow hemp with high CBD content (as well as keeping THC content low). So far, it seems that CBD hemp has similar nutrient requirements to corn.

Some farmers and researchers recommend splitting fertilization between a pre-plant application and a side-dressing in July, aiming for between 125-200 pounds of nitrogen per acre. Dr. Sandler recommends applying around 100-120 pounds of nitrogen per acre at planting and around 50 pounds about one month later. The second application is timed to meet the plant’s increased nitrogen requirements when flowering. Potassium uptake is also at its peak at the start of flowering and the plant needs around the same quantity of potassium as it does nitrogen.

There are no approved herbicides made specifically for growing hemp—a benefit for growers experienced at managing weeds organically. Weed management starts with field prep. Cover crops, either to be tilled or roller-crimped, can help to build the soil and suppress weeds leading into the season. Spacing is the second major consideration. Wider spacing allows for mowing of a living groundcover. Plasticulture allows for mowing or cultivating between the rows and hand-pulling weeds next to the plant. Some growers in drier climates have used straw mulch, but Dr. Sandler is concerned that it may contribute to moisture-related disease issues in more humid climates. Availability of labor and equipment are the other key issues; your weed management plan will largely depend on your system.

Managing pests and diseases in any new crop can be challenging. As McHugh said, “I can’t just easily identify things like I can with corn, soybeans, or small grains.”

Scouting is the first step to successful pest management. While there are not any EPA-registered pesticides for use on hemp, some state departments of agriculture recommend using 25(b) minimum risk pesticides, which are considered to “pose little to no risk to human health or the environment” according to the EPA. Check with the agriculture department in your state (and your organic certifier) to see which pesticides might be allowed.

Two of the key hemp diseases are powdery mildew and gray mold (Botrytis), according to Dr. Sandler. They are both related to moisture on the leaves, so plant spacing and ventilation are two preventive practices that may help give your plants a competitive edge. Control of these diseases is important because even a small amount of mold in the flowers can make the crop unsaleable. The same organic pesticides that are used on diseases like powdery mildew on vegetable crops can be effective on hemp. Examples include products that contain neem oil or potassium bicarbonate. Again, check with your certifier and your state’s 25(b) minimum risk pesticide list to make sure a product is allowed for you to use.

Some major insect pests are aphids, mites, thrips, Eurasian hemp borer, corn borer, and corn earworm. European corn borer and Eurasian hemp borer have been reported across Wisconsin in 2019. Bacillus thuringiensis (Bt) can be effective for control of borers and worms.

McHugh ran into variegated cutworm on his crop. To control them, he pulled them off by hand and put them in a bucket of soapy water. He explained that his main plan for dealing with pest pressure is to create optimum plant health and going four or five years between hemp or other host crops.

Pollen Drift
One major risk factor with CBD production is pollen drift. Farmers plant feminized seed and cull male plants because the CBD content plummets when the female plant is pollinated. A reasonable expectation for CBD content as a percentage of dry weight is above 8%, but when the female flowers are pollinated the CBD content can go below 4%. Beyond just cutting your saleable product in half, you probably would not even be able to find a buyer for hemp biomass with 4% CBD content.

Pollen can travel up to 10 miles, so you don’t just have to be aware of what is in the neighboring field. Susan Candee, a farmer in southern Wisconsin, said she drove a perimeter of 20 miles to get to know what other farmers are growing. Because hemp was historically grown in Wisconsin, some areas have high populations of wild hemp, also known as ditch weed. McHugh said he found some along a local bike trail and destroyed it.

Before deciding to grow CBD hemp, take stock of the wild hemp populations and other forms of hemp production in your area. If this risk is too great, you may have to grow CBD inside a greenhouse or find creative solutions to keep pollen off the female flowers.

Testing for THC is required for every variety of hemp from every field where it is grown. These tests are $250 each, and the farmer has to notify the state 30 days before harvest. The crop must be destroyed if it has over 0.3% THC.

Choosing the right seed genetics is the first way to keep the plant from “going hot.” The second is to provide ideal growing conditions since hemp produces THC in part as a response to stress. Overfeeding phosphorus and, in later growth stages, potassium will put your plants at greater risk of crossing the THC threshold. Every variety of hemp will eventually pass the THC threshold if you leave it in the field too long.

Candee said she plans to test her crop regularly as harvest time approaches. Even though the state only requires a single pre-harvest test, she wants more peace of mind about THC levels to mitigate some of the risk. While crop insurance will be available for hemp in 2020, the USDA’s press release announcing the change also noted that “hemp having THC above the compliance level will not constitute an insurable cause of loss.”

Harvest is one of the most important aspects of hemp production. A crop harvested and dried incorrectly can be destroyed. Left to grow, a hemp plant will produce only one flower. CBD is produced in the trichomes (glandular hairs) on the surface of female flowers, so if you continually top the plant you can induce bushing to produce more flowers.

The flowers are ready to harvest when the trichomes turn from a clear white to a milkier white color, according to Dr. Sandler. Harvest times will vary by planting date, day-length, and cultivar but will generally be from mid-September to mid-October in the Upper Midwest.

Growers harvest the entire plant (including the stems, leaves, and flower buds), just the flowers, or trimmed flowers. The CBD content as a percentage of biomass will be least with the harvest of the entire plant and most with trimmed flowers. Check with your buyer about CBD percentage requirements or requirements for what form your harvest must take. Some buyers require a minimum of 8% CBD.

Harvesting CBD is labor-intensive as it is usually harvested by hand. If you do not have enough labor available to harvest the crop on time you can drastically reduce your CBD content (as well as increase your risk of passing the THC threshold). Large-scale growers can invest in tractor attachments and other tools for harvesting and removing the flowers from the stalks. Some examples are the KIRPY CBD Hemp Harvester and the Hemp Harvest Works Hemp Handler. Both appear to work similarly, as they were reengineered from tobacco-harvesting machinery.

CBD hemp should be dried as quickly as possible. Ventilation and humidity control are very important. Heat can degrade the CBD content, so fans are used instead. The ideal conditions for drying CBD hemp are between 60 and 70 degrees and 60% humidity. If there is too much moisture, the crop can mold quickly, which will make it unsaleable. In the Midwest, it should be dried under a roof and out of direct sunlight. Drying facilities have to be clean and free of animals, birds, and insects. At a large scale, hemp drying machines can aid this process.

Organic Certification
Any certified organic CBD product must be from a certified organic crop that’s processed at a certified organic facility. It may be difficult to find certified organic processers to extract CBD, but there are several in the process of certification now that should be ready in time for the hemp harvest.

Because certifiers are regulating federal law they can’t certify products that are allowed in some states but aren’t allowed federally. They may be wary of certifying CBD products because of their murky federal legal status. Some certifiers won’t certify CBD as a food product or in a food product. Some will certify CBD as long as the label is not making a health claim or has a disclaimer along the lines of “this claim has not been evaluated by the FDA.”

Seed treatments can be an issue in organic production. MOSA’s Kristen Adams, who is a nationally recognized expert on hemp certification, said there are two commonly used substances that can be applied to hemp plants to produce feminized seed. The first is colloidal silver. It is allowed if you can verify that it is natural, which Adams said is “very hard to do.” The second is gibberellic acid, which is allowed in organic production.

To get feminized seed, when the plant starts to flower, you spray the plant with either gibberellic acid or colloidal silver. Then the plant only produces female seeds because it stops the production of the male chromosome. For certification purposes, the seed is not considered treated because the plant is treated before it produces seed. As long as the harvested seed is not treated with other prohibited substances, and you conduct an organic seed search that shows that it is not available as organic, you can plant the feminized seed produced with either gibberellic acid or colloidal silver. To produce certified organic feminized seed, you’d have to use feminized pollen from a gibberellic acid treatment to pollinate a certified organic mother plant.

Certifiers have to verify that producers are in compliance with their state hemp program, and they will ask you to submit information about your state hemp license. In order for the oil or the end product to be certified organic, the processing facility also has to be certified. Contact your certifier early in the process to make sure you are in compliance.

Promise of CBD
There are still more questions than answers when it comes to growing and marketing CBD hemp. It may end up that the Midwest is best for fiber production and is too humid for other kinds of hemp. It may be that pollen from ditch weed makes growing CBD outdoors impossible. CBD as a health craze could be a flash in the pan and the price could plummet as demand drops. Or, it could be the next major cash crop for farmers in the Midwest.

The kind of farmer who is willing to take on the challenge is someone who enjoys experimentation and is not afraid of taking risks. Most farmers are growing CBD because they believe its medicinal properties offer an alternative to the debt and addiction that can come with modern medicine. There are many challenges and a lot left to learn. If growers in this region can be successful growing CBD hemp, and if they can make their voices heard in building equitable supply chains, CBD hemp could transform rural communities.

Chuck Anderas is a MOSES organic specialist. Reach him through the Organic Answer Line: 888-90-MOSES.


Online Resources for Hemp Growers:

University of Wisconsin-Extension’s hemp website has webinars, blog posts, and a buyer/seller list.
Listserv to ask questions and offer answers about hemp
Rodale’s industrial hemp trial
List of pesticides that may be used on hemp in Wis.
List of licensed seed and transplant sources
Searchable database of pesticides approved in Wis.


State Hemp Sites:



From the September | October 2019 Issue


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