Temperate regions of Australia produce low-THC cannabis crops grown for their edible seeds and seed oil. Hemp seed crops release clouds of male pollen grains, each with the potential to fertilize a female flower and form a seed. The male pollen plants then wither and die.
Photos by Robert C. Clarke unless otherwise noted

Today, a multitude of cannabis seed companies are producing more seeds than ever, and now that laws are changing, more and more cannabis crops are being grown outdoors from seed.

Broadacre (farms that produce crops on a large scale) CBD producers are leading the return to growing crops from seed. Auto-flowering THC and CBD varieties are gaining popularity (especially in regions exceeding 40° latitude north or south) where summer days are too long to induce flowering in most cultivars.

But the growing of seed crops can cause problems. Put simply, the airborne pollen from seed crops poses a serious threat to the much more lucrative business of growing seedless drug cannabis flowers.

Left: Modern-day seedless drug cannabis crops are grown from genetically identical female cuttings so that no pollen and no seeds are produced (photo by Mel Frank). Right: East Asian farmers harvest their highest-quality hemp fiber crops before they flower, so no pollen or seeds are produced.

Biology Meets Agronomics

Most plants produce flowers bearing both male and female sexual organs, and the majority of these are pollinated by various animals ranging from insects to bats. In natural settings, Cannabis plants present an exception to the norm, with millions of pollen grains borne on male plants that release their genetic potential into the breezes. Those pollen grains that complete their reproductive journey land on the receptive ovule-containing flowers borne on female plants and fertilize them, the seeds maturing a few weeks later. Individual male plants die within a few weeks, leaving the remaining pollinated female plants to mature their precious seeds (the next generation) without competition for water, nutrients and sunlight.

In another exception to the norm, separation of the sexes is the key to horticultural cannabis flower production. Both THC and CBD drug cannabis crops are grown without seeds. The sinsemilla (seedless) method is commonly used to enhance the production of secondary metabolite target compounds such as THC, CBD and aromatic terpenes. When seedless Cannabis is grown for drug production, any seeds are undesirable and drastically lower the value of the dried flowers. Early sinsemilla growers realized that they could simply remove all male plants so no seeds formed, and their precious females would develop much larger and more potent flowers. Female plants with desirable traits were vegetatively reproduced to multiply the clones in common production today, and there are no longer troublesome male plants in most modern drug crops.

We believe seeds producing all-female crops will be widely used for broadacre THC and CBD production in the near future. Why grow any males when you can grow only females, and why keep mothers and make cuttings when you can more easily, efficiently and cheaply sow seeds that are essentially a female cutting in seed form?

This sounds like a perfect scenario. What could possibly go wrong?

Enter Traditional ‘Industrial’ Hemp

In Europe and North America, hemp fiber crops have traditionally been harvested upon reaching technical maturity when the male plants begin to shed pollen. In eastern Asia, hemp fiber crops destined for fine textile production are harvested before they flower, and therefore no pollen or seed is produced. No flowers, no pollen and no problems. The timing of a fiber crop harvest—either before or after it releases pollen—determines whether it poses a threat to neighboring sinsemilla cannabis growers. Depending on cropping techniques, fiber hemp production can be compatible anywhere. The real issue is not about fiber hemp production, but seedless drug cultivation. However, the situation differs with hemp seed crops.

Hemp-seed crops are grown specifically for seeds sold primarily to the food and body-care industries. Hemp seed and seed oil are more in demand than at any other time in recent history, and the profitable growing of hemp seed is increasing at suitable temperate latitudes worldwide. Based on their common environmental needs, seedless drug cannabis thrives in the same agricultural niches as hemp seed crops, and this can lead to competition between these agronomically incompatible crops.

Long-distance Cannabis pollen transport is well-documented. A single male Cannabis plant can produce millions of pollen grains that are easily carried on the wind. Each summer, allergenic pollen traps installed along the Mediterranean coast of southern Spain collect Cannabis pollen that drifts across 100 miles of open sea from hashish fields in the Rif Mountains of Morocco.

Field-grown hemp seed crops are agronomically and economically incompatible with drug cannabis crops, and growing them within the range of pollen travel will likely result in conflicts. Even cannabis plants grown in greenhouses and grow rooms can become fertilized by pollen that enters through the ventilation system. It is of note that during the early days of industrial hemp cultivation in the Netherlands several indoor and glasshouse sinsemilla growers reported finding seeds in their normally seedless crops. (Tip: High efficiency particulate air (HEPA) filters effectively remove pollen from air intakes in sealed grow rooms.)

In the sinsemilla setting of zero tolerance for seeds, long-range pollen drift, especially outdoors, sounds frightening. Reactionary voices within the cannabis community have raised the alarm, but is there a real threat? How are the cropping strategies of growing seeded hemp cultivars for their CBD content versus growing seedless drug varieties for THC and/or CBD content playing out across North America and worldwide?

HempFlax BV farmers in Romania harvest hemp fiber, hemp seed and CBD from the same standing crop. Multi-cropping strategies are the most economically viable for broadacre cannabis commodity farming.

International Precedents and Lessons

In response to increased market demand for both hemp seeds and CBD, traditional hemp cultivars’ flowers are now commonly grown to produce both CBD and seed. Hemp stalks are harvested for their economically valuable fiber from both the male and female plants, while female flowers produce economically valuable compounds such as CBD, THC and aromatic terpenes as well as seed. Broken flowers remain after threshing hemp seeds. Until recently, this CBD-rich waste was burned in the fields. Now, CBD is extracted from the flower biomass. Several hemp cultivars contain sufficient amounts of CBD to make extraction profitable.

We perceive the most lucrative agronomic model to be triple cropping an existing approved (low THC) industrial hemp cultivar for fiber, seed and CBD. HempFlax BV, a hemp cultivation and processing company with cultivation sites in the Netherlands, Germany and Romania, harvests all three products from the same standing crop. This lucrative cropping strategy allows a farmer to make agronomic decisions based on three commodity markets—fiber, food and drug—and we predict will prevail in the near future among progressive farmers worldwide.

China and Romania are traditional hemp farming regions without commercial seedless drug cannabis production. Manitoba farmers have dominated North American hemp grain seed production for 20 years and have established Manitoba as a hemp seed producing region. Few outdoor sinsemilla growers would attempt to establish production there. Rather, drug cannabis is more often grown indoors in urban areas, and in glasshouses and outdoors in regions without hemp seed crops. To that end, conflicts are rare, but could still arise.

In most drug cannabis producing regions (e.g., Colombia and Mexico, as well as the Caribbean, Africa and Southeast Asia) crops are grown seedless to increase the flowers’ potency. It would be unwise to attempt growing seeded crops in these regions. In all these examples a pairing of local traditions with economic factors determines whether Cannabis crops are grown with or without seeds.

Several of the aforementioned agricultural business models could prove economically viable in any given region, but many are not mutually compatible. The agricultural differences among broadacre, greenhouse and indoor production create an economically segregated terrain where few conflicts have yet to arise. However, conflicts will undoubtedly arise unless specific cannabis growing regions become set aside for female-only growing of seedless drug crops.

North American Constraints

In the face of steadily expanding seedless drug crop acreage bolstered by supportive legislation across America, will there remain anywhere for hemp grain seed crops to make their long-awaited comeback? Will the U.S. always rely on Canada and China for healthy hemp seed products?

The expanding range of Farm Bill hemp (high-CBD seedless flower) production in 2018 reached 23 states. Colorado and Montana, leaders in U.S. hemp production, each grew more than 20,000 acres, followed by Kentucky and Oregon with around 7,000 acres each, and Tennessee, North Carolina, North Dakota, New York, Nevada, Wisconsin and Vermont had from 1,000 to more than 3,000 acres under licensed cultivation. More than 78,000 acres of Farm Bill “hemp” were grown in 2018 nearly, tripling the less than 26,000 acres grown in 2017.

Now, private citizens as well as agricultural entities across North America are increasingly allowed to grow both industrial hemp (including hemp grain seed crops) as well as seedless drug cannabis for medical and adult use. In some areas this situation sets the stage for potential conflicts until industry self-regulation and enlightened agricultural policies take effect. In the meantime, most regions appear to offer opportunities for everyone.

However, the situation is becoming increasingly convoluted. The U.S. landscape is a complex puzzle of differing jurisdictions, each with its own evolving cannabis scenarios and range of regulatory solutions. Until the advent of the CBD industry, industrial hemp cultivation held little attraction in most regions of the U.S., and largely due to prohibition, most seedless drug cannabis was grown either in remote rural or insular urban settings isolated from any hemp pollen. Many newly cannabis-tolerant jurisdictions may allow Cannabis plants to be grown for whatever end use someone might choose—be it fiber, seed and/or drug.

In many regions across North America, sinsemilla growers arrived decades earlier than the recently arrived “hemp” growers. North American sinsemilla growers pioneered drug cannabis cultivation and established their turfs long ago, largely in agriculturally marginal rural areas not well-suited to broadacre hemp fiber and seed production. California presents several cases in point.

Sparsely populated rural regions of Northern California have been the primary producers of sinsemilla since the 1960s, and since the 1980s indoor, artificial-light growing has become increasingly popular in more urban regions with access to the electrical grid. The established agricultural precedent in both scenarios is drug cannabis production. So far, industrial hemp and hemp seed crops have had little, if any, effect. It is really up to the growers of seedless high-THC and high-CBD drug crops to defend their turf (especially outdoor cultivation, which is common in California and expanding elsewhere) from the potential pollen threat of seeded crops.

On the West Coast, state cannabis grower associations are striving to establish sinsemilla production regions based on climate and terroir similar to the appellation system used in wine branding. These groups have grown organically from illicit rural grower communities and provide good examples of self-regulation of our industry from within by a group of peers. Appellation membership will likely require qualified farmers to grow only female plants from cuttings, and the sowing of seeds (a possible source of male plants and contaminating pollen) will be strictly controlled.

Both industrial and medical hemp crops are most profitably produced under broadacre agriculture, while sinsemilla flower crops are most profitably produced under glass. California’s Sacramento, San Joaquin, Imperial and Salinas valleys present examples of regions where potentially conflicting business models may clash. Many growers in these traditionally broadacre farm and orchard regions have switched to glasshouse production of vegetables, bedding and house plants, and cut flowers. Sinsemilla flower growers will move into regions where glasshouses are readily available, and local regulations usually stipulate that existing glasshouse infrastructure must be utilized. This places seedless growers near neighboring broadacre farms where it is also economically feasible to grow fiber and seed hemp.

Southern California provides an even more dynamic terrain. As urban areas grow, cultivators occupy former farmlands that still border active agricultural zones. And, traditional broadacre farming regions that previously grew few if any sinsemilla or hemp crops are now open to the growing of either one or both.

These scenarios exemplify the need for agricultural authorities to take responsibility for local regulation of their cannabis industries before conflicts between growers arise. There are few established historical and agricultural precedents for either sinsemilla or hemp growing in prime agricultural regions. These areas produce many crops profitably, and as with other crops, are where the future of commercial cannabis production for many different products will be focused.

Solutions

How will various jurisdictions with differing constituencies and priorities create equitable policies for the control of stray cannabis pollen in sinsemilla-only areas?

People are quirky, and there will always be a few individuals who will grow fiber or seed hemp in regions where drug crops are commonly grown, and there will be others who try to grow seedless cannabis flowers where seed hemp is well established, but these will be exceptions to the local norms. Across North America, effective and fair regulation of our burgeoning cannabis industry will largely rely on understanding which branch of our industry was established in each region first, and whether a precedent exists for its continuation; ultimately, policy decisions will be based on which end use offers the most income (including compliance costs, local trade, employment and taxes) to local and state jurisdictions.

Local, state and federal agriculture organizations should ultimately control cannabis licensing and permitting, first in local jurisdictions and eventually nationwide. Agricultural officials must take stock of regional conditions and become sensitive to the unfolding cannabis industry and determine the traditional basis for cannabis economics in their region. If sinsemilla growers have contributed to the economic viability of their local economy, albeit illegally, then they should be invited to have a strong voice in determining future cannabis policies and regulations.

Mojave Richmond is the developer of many award-winning varieties such as S.A.G.E., which served as a springboard for creating many notable cultivars. Richmond is a founding member of the international consulting company BioAgronomics Group. info@bioagronomics.com

Robert C. Clarke is a freelance writer, photographer, ethnobotanist, plant breeder, textile collector and co-founder of BioAgronomics Group Consultants, specializing in smoothing the transition to a wholly legal and normalized cannabis market. info@bioagronomics.com