Physical indicators of mature crops include golden to reddish brown pistils and cloudy trichomes on the flowers (Figure 4) but potency testing (see above) should inform harvest decisions. Hemp harvest can be reminiscent of tobacco harvest. Plants are often harvested by hand. Mechanized equipment is available but is currently very expensive. Large scale operations often have teams of laborers cutting plants, stacking them on trailers or hay wagons, and transporting them to the area where the plants will hang to dry. Growers use different tools for cutting hemp stalks ranging from machetes to sickle-bar mowers to motorized pole saws. Plants are hung in a dark, dry area with good air circulation. To prevent mold, plants should not be so densely packed in the hanging area that air does not move well between them. Tobacco barns are commonly used in Kentucky, as are high tunnels with double layered shade cloth or warehouses with adequate space and ventilation. Some large scale growers use ovens to dry the plants at 120-150°F (higher temperatures will cause degradation of cannabinoids). The goal is to get the plant material to 12% moisture or less to inhibit mold. After drying the material is ready to be marketed. Growers for will often shuck the flowers into large polypropylene mesh supersacks for storage and transport to a processor.
Figure 4. Mature female hemp flower ready for harvest. The inset shows a close view of the reddish brown pistils that indicate maturity in Cannabis. To avoid going over the 0.3% THC limit, actual harvest decisions should be based on results of potency testing as well as physical indicators. (Photos by Jonathan Palmer).
Many pitfalls can be avoided by obtaining seed or clones from trusted sources. Many cultivars have been bred in Colorado, Orgeon or other states that have legalized marijuana and are essentially marijuana cultivars that have been bred for reduced THC. They may not be stable or uniform when grown from seed and they may not perform as expected in Kentucky agroecosystems. This can lead to exceeding the THC compliance threshold, particularly in cultivars having high CBD contents. Preliminary results from work at Kentucky State University has indicated that plants with more than about 8% CBD tend to be close to or over the 0.3% THC threshold. Producers should also be aware that “feminized” seed is often not truly feminized and can have a higher than advertised ratio of male to female plants.
bred in Colorado, Orgeon or other states that have legalized marijuana and are essentially marijuana cultivars that have been bred for reduced THC. They may not be stable or uniform when grown from seed and they may not perform as expected in Kentucky agroecosystems. This can lead to exceeding the THC compliance threshold, particularly in cultivars having high CBD contents. Preliminary results from work at Kentucky State University has indicated that plants with more than about 8% CBD tend to be close to or over the 0.3% THC threshold. Producers should also be aware that “feminized” seed is often not truly feminized and can have a higher than advertised ratio of male to female plants.
This industry is new and the market is volatile. Prices for hemp grown for CBD extraction dropped by over 78% from fall 2018 to fall 2019 and have remained low in 2020. Many contracts with farmers have been voided by processors and some processors have filed for bankruptcy. Production in 2019 exceeded demand and many farmers were not able to sell their crops. Specific demand for organic crops remains as uncertain as the industry in general.
Hemp may be a new opportunity for organic farmers and is an additional way to diversify a farm operation or crop rotation. There is significant interest from consumers in cannabinoid products derived from hemp. However, farmers interested in trying hemp production should make sure they understand the risks. Good advice for new hemp farmers is to start small, learn the lifecycle of the plant, don’t plant or invest more than you can afford to lose, and make sure you have a solid marketing outlet for crops before planting. An excellent resource for developing a production budget is the University of Kentucky’s Hemp & Enterprise CBD Budget Model (see references: Mark and Shepherd, 2020). It is recommended that a lawyer review any marketing or processing contracts. This crop and the associated industry are new to the U.S. agricultural landscape and there are many uncertainties, including a lack of FDA approval on most products. There is also guarded optimism that as the industry becomes more established, more products gain FDA approval, and consumers become more educated on non-intoxicating Cannabis products, the cannabinoid market will stabilize and organic products will likely have a share of this market.