Close up of hemp seeds

Growing Hemp for CBD

With legalization of cannabis, we can expect to see hemp agriculture incorporate strains that are more suited to the production of CBD. Until now, the industry has focused on food seed. In this article we examine the state of hemp agriculture in Canada and the United States, and look at how cultivating hemp for CBD production might require new techniques.


Since the US Farm Bill and the Canadian Cannabis Act, both in 2018, the Hemp industry has experienced unprecedented interest and momentum. However, since hemp became legal about 20 years ago in Canada, the industry has been driven by the demand for food seed which has been the most viable market.  Grain production easily dominates the crop use for industrial cannabis in Canada. Because of this primary focus, almost all the pre-approved cultivars from Health Canada are strains that produce higher grain or fibre yields with little to no genetic focus on the cannabidiol production. Prior to the Cannabis Act, Canadian farmers were not even  allowed to harvest the leaves or flowers of their crop. 

 In many aspects, the legislation has over restricted the Hemp industry in Canada compared to the US markets. In the US genetic diversity and breeding of high CBD strains is more prolific. Moving forward we will see more high CBD strains being approved in Canada. The 2020 cultivar list is expected to be released in February 2020. 

Having a genetic pool of high CBD producing plants could mean the difference between yields of a 15-25% return versus our current strains which can get up to 7-10% in perfect conditions and with extensive crop management.  This is a huge difference in profit margin for growers and will take a few years to work itself out.

 Some of the notable medical CBD hemp strains are: Cherry Wine, Charlotte’s Webb, Electra and Lifter, none of which have been allowed in Canada yet. In the US, farmers can grow hemp, extract the CBD and make products to sell directly to consumers. This makes the micro-grow opportunities a lot more viable in those states allowing extraction on hemp stands of less than 10 acres. In Canada, farmers must sell their flower crop to a licensed producer or acquire a few expensive licenses making this vertical integration prohibitive and selling directly to consumers almost impossible.

Cultivation Techniques 

Growing quality flower poses many challenges on the industrial scale and is quite a different process than growing grain or fibre. To grow a high yielding flower crop, the female plants which produce the CBD must not come into proximity to pollinating male plants. In this aspect, growing a flower crop of hemp is very similar to growing THC containing strains of cannabis. If the flowering females are pollinated, they will spend energy making seeds and cannabinoid production is greatly reduced. 

Cannabis growing in a greenhouse

On farms across Canada, the hemp industry has been using conventional farming techniques which don’t work as well for flower production. Many producers in the US are moving to cloning female mother plants or buying expensive feminized seeds. This reduces the chance of wasting time and energy growing a male plant which will need to be removed during the vegetative cycle.  By planting clones or feminized seeds the farmer can ensure a drastic reduction in male plants. Standard seeds on grain and fibre operations can contain as much as 50% males. The removal of male plants is labour intensive and can take a lot of attention and time on large scale farms.

In the US three states are leading the charge in CBD production; Colorado, Kentucky and Oregon all have strong hemp farming programs and state-wide legislation allowing the extraction from flower. In Colorado, which is arguably the center of the country as well as its legal cannabis epicenter, almost 400 registered growers are focusing on hemp flower with more than 2 million square feet of indoor production as well as 12,000 acres of outdoor. 

Many quality flower operations in the States have moved away from the conventional cash crop format that we have in Canada and are growing smaller well-maintained plots or indoor gardens. This allows producers control over the environment,  preventing the pollen contamination that is common in areas with nearby hemp crops or wild varieties of cannabis.

 Irrigation plays a big part on these farms. Some plants are grown in the ground, but many are planted in bagged rows or in pots. In more northern latitudes, starting the plants in a greenhouse is a great way to increase yield and extend the growing season. Most hemp is planted in early June and begins to flower some time in August when the daytime photoperiod gets to 12hrs or less.

Hanging Cannabis plants to dry


On most hemp farms in Canada, the harvest is done with combines that shake the grain out of their crop.  On grain production farms only the seed is harvested and the rest of the plant is ploughed back into the field. When flower is harvested, a  grower can hand cut their plants down but larger operations use a swather or stripper. Although some equipment can strip just the flowers, it is most common for the full plant to remain intact and left hanging indoors for a few weeks to allow for drying. Plants are hung upside down and spaced to encourage even circulation. Adding fans to the drying area is critical to prevent any mold from developing. Mold can spread quickly and would diminish the quality and value of the crop. Some farms have drying equipment to speed up the process and prevent spoilage. These specialized drying units have been designed from or repurposed from the tobacco industry. Once the flowers are dry, they can be stored or sent to the extraction facility where the CBD can be separated from the biomass.

This is an exciting time in hemp agriculture. Hemp is a versatile plant and the industry is set to explode with all the interest in new the hemp products that are becoming available to consumers.

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