How The Pollen Wars Are Hurting The Cannabis Industry
And what we can do about it.
While medical marijuana and hemp are both varieties of cannabis, the way these plants reproduce can make vast differences in the type, potency, and quantities of the chemicals they express. As medical marijuana and hemp farms increase in size and presence, a resultant war is heating up in the very air around them.
Let me explain. When hemp and cannabis cross-pollinate, the quality of each diminishes: Cannabinoid potency in cannabis females can reduce, while THC in hemp can increase. This is a recipe for disaster. Cross-pollination ruins crops and costs untold financial damage.
How pollinations works
Cannabis transmits its DNA sexually through the act of pollination. Males develop loose flower clusters that begin as pods. The pods swell and fill with pollen. When the male is mature, and its pods are ready, the pods burst open, spraying pollen from its anthers. That pollen carries on the air seeking to fulfill its genetic mandate of fertilizing as many females as possible. Pollination occurs when pollen reaches the female, triggering female plants to produce seeds.
Cannabis can be both monoecious (plants that can be both sexes, hermaphrodites) and dioecious (plants that have distinct female and male). Both types of cannabis exist in nature, although hermaphrodites mostly only happen when the cannabis plant gets stressed. If a female cannabis plant senses impending death, it will begin to express male characteristics to auto-pollinate.
How it's destructive.
A 1998 study found that pollination decreased the yield of essential oils in cannabis flowers by 56 percent. While allowing en masse pollination produces a lot of seeds, the resultant buds suffer diminished medicinal value. When plants invest energy in seed production, they make less CBD. If you are a non-medical commercial hemp or seed producer, this may be exactly the sort of outcome you seek from your crop. But mass pollination is anathema to the medicinal producer.
Fathers, lock up your daughters.
In the 1970s, marijuana growers found the longer female plants go unpollinated, the more flowers they produce and the larger they get. This revelation began the modern industrial practice of selecting out males and positive-female selection through clonal propagation or sowing of feminized seed. In a very real sense, the preservation of cannabis female virginity translates to actual dollars. Hence most modern marijuana is seedless sinsemilla, while seeded crops are regarded as inferior.
Combatting the problem
Pollen's increasing prevalence has caused cannabis producers to ruminate on such topics as its transport on the wind and related impacts of wind speed, direction, precipitation, humidity, topography, and physical barriers.
The ability to isolate growing fields is one strategy used to mitigate undesired pollination. But geographic isolation is apt to prove decreasingly effective as more pollen enters the atmosphere. There may be little to be done, as pollen can travel for miles, and in the right circumstances, it can even be picked up by the jet stream and travel the world.
In late 2019, the USDA funded a $500,000 study on pollen drift. Certain municipalities have also tried to get ahead of the problem through the enactment of isolation ordinances. For example, in August 2018, the city of Snowflake, Arizona passed an isolation ordinance to protect a large marijuana grow operated by Copperstate Farms. Many states also have crop registries so that locations and distances can be identified and maintained. But often data is voluntary and resultingly inaccurate.
Besides physical distance, other mitigation methods are also used—such as misting water between crops to knock pollen out of the air, strategic windbreaks, border crops, or rings of trees. However, physical isolation is best accomplished indoors with air filtration systems. Yet for all its gains, indoor isolation dramatically increases the cost of cannabis production and makes the operation substantially more electricity-dependent. Given the enormity of scale, indoor grain or fiber hemp cultivation is simply not reasonable.
What to do?
If you are a cultivator, your failure to give consideration to pollen mitigation is tantamount to malpractice. If you are scouting cultivation sites, you must consider the neighborhood in terms of tens of miles of radii. Consider, too, the future. As home growers in recreational marijuana states flood their suburban atmospheres with pollen from their porch “hobbies.” (Prepare for disappointment, home growers, for you are filling your air with the very means of your future gardens’ undoing.) If you are an investor, ask to see a pollen mitigation plan before you invest. Don’t see one? Walk. A single crop loss can cost tens of millions of dollars.