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Unpredictable Biology And Stringent Regulations Turn Up The Heat For Hemp Farmers

Courtesy Mike Workman
Acres of hemp growing early in the season.

This story is Parts 3 and 4 of a four-part series on the hemp industry in Colorado. Read and listen to Parts 1 and 2 here.

Colorado’s top three commodity crops are wheat, beans and corn. But there’s a new kid on the block: hemp — and its confusing sex life and relationship to marijuana is complicating matters.

Prohibition relegated cannabis to basements and garages where it would be grown in secret for decades. But as regulations loosened, hemp has moved to outdoor fields and industrial-size greenhouses.

Mike Workman owns New Earth Hemp Company out of Laporte, Colorado, and even he is humbled by this shift in scale.

Seré Williams / KUNC
Cannabis pollen coats the walls of a jar of male flowers stored by a hemp breeder.

“Whatever you think you know, you don’t know when you’re trying to plant an acre of it,” he said.

Outdoor growing is a lot cheaper than indoor growing, but it comes with its own set of challenges.

“Then you have, you know, bugs, weather, hail, snow,” said Ted Duerr, a hemp farmer, breeder, and co-owner of BDG Genetics in the small town of Frederick in southern Weld County. “Pollen is one of the biggest things.”

Plants produce pollen. So, how could that be an issue?

The unique reproductive life of hemp

This is where science – and sex – come into play. As a plant matures, it produces a flower. Males produce pollen, which pollinate female flowers, which in turn develop fruits – also known as seeds.

Most plants contain male and female parts on the same plant, sometimes even in the same flower. But hemp is unique — one plant will have only male flowers while another will have only female. And females can transform.

Female hemp plants are hermaphrodites, meaning they can turn into males. Depending on what you’re growing hemp for -- fiber, seed oil or the chemical cannabinoids – the unexpected sex-switch can be a problem.

Seré Williams / KUNC
This unfertilized female hemp plant has only female flowers. The wispy white "styles" from the female flower reach out in search of pollen.

If you’re in it for the fiber, pollen doesn’t affect your crop, so it doesn’t matter what sex your plants are.

Seré Williams / KUNC
Hemp seeds can be planted to grow the next generation or pressed into oil -- similar to canola, soybean, or vegetable oil. When you see "hemp oil" advertised on a bottle of conditioner, the oil is from the hemp seed and should not be confused with the oil that contains cannabinoids from the hemp flower.
Seré Williams / KUNC
Flower oil (the main source of cannabinoids) covers the spike of a hemp plant, each droplet perched on a plant hair called a trichome.

If you’re growing hemp for seeds to press into oil, you want a female plant to be fertilized by a male’s pollen. As Ted Duerr explained, “those strains need the males in there to pollinate and create the grain in the flower.”

But to grow hemp for the flower – or cannabinoids – you need a virgin female flower that never comes into contact with pollen.

According to Workman, “you can revert females into a masculine form, but you can’t really revert males into a feminine form.” This is a problem, because once a female plant turns into a male, it can fertilize other females in the field, and make the flowers develop seeds.

“For CBD production, high CBD genetics, all these people that are going for smokable flowers, CBD oil, everything like that, you do not want males in your field, because you do not want seeds in your flower,” said Duerr.

Since pollen travels on the wind, Duerr says a neighboring hemp crop with male plants could impact the outcome of your field. This happened last year.

“A guy that we know did 600 acres of grain and fiber and there was multiple people around him that were trying to do smaller acreage for CBD oil and smokable flower, but needless to say, all their crops were ruined for what they wanted to do ‘cause they all became seeded,” he said.

Even with current genetic techniques, the biology underlying the sex switch is not well understood. It could be dependent on the environment.

Other important traits — like THC concentration — are dependent on the environment, too. But while a male plant won’t make your crop illegal, too much THC will.

Seré Williams / KUNC
Hemp seeds develop on a cannabis plant bred for specific characteristics.

The deal with cannabinoids
Listen to part 4 of the audio here

THC is a psychoactive chemical compound in marijuana. It’s what gets you “high” when it’s smoked or consumed. THC is just one cannabinoid, but the plant produces over 100 different cannabinoids – like CBD and CBG – that hemp growers are after for medicinal uses. CBG is produced first, and then specific enzymes convert CBG into either CBD or THC.

Screen Shot 2020-09-01 at 8.46.41 AM.png
Seré Williams / KUNC
CBG is converted into either CBD or THC. (Note that the acidic form of these compounds predominantly exist in the plant and are converted into the decarboxylated form — shown here — with heat.)

While cannabis was being grown indoors and in secret -- during prohibition – the plant was grown for one purpose.

“If it had not been for prohibition, cannabis and hemp would not be what they are today, and they would just probably be, it’d be like, we’d all be smoking hemp, we’d all be smoking rope,” said Workman.

Marijuana breeders continue to coax CBG into THC, thereby increasing THC content. According to the Drug Enforcement Agency, average THC concentration increased from 4% in the mid-90s to 12% today. THC can be found as high as 25% at some dispensaries.

But now, breeders need the plant to take the other fork in the road: the path that turns CBG into CBD.

For hemp growers, like Workman and Duerr, THC levels are strictly regulated and cannot exceed 0.3%.

“It takes one day extra in the field for you to go from safe to hot. That’s problematic. It’s basically a scenario that can turn innocent farmers into criminals,” said Brett Eaton, owner of Green Cherry Organics, a hemp breeding company in Fort Collins.

Before a farmer harvests, the Colorado Department of Agriculture samples flowers from a hemp field to test for cannabinoid levels.

“That’s the worst part of this job,” said Brian Koontz, the hemp program manager with the Colorado Department of Agriculture. “A lot of it’s very fun, but come September, October we start getting hot results back from the lab. When I say ‘hot results’ that means it’s gone above the allowable three-tenths of one percent,” he said. “We demand by law that it be disposed of in a manner that’s irretrievable and does not enter the stream of commerce and does not leave the registered land area.”

Last year, 99 hemp fields in Colorado were above the limit. They were either burned or plowed into the soil on site.

Breeding the magic plant

Eaton and other hemp breeders are trying to find the perfect variety – a female plant that would never transform into a male and never produce too much THC (while producing plenty of other cannabinoids).

Seré Williams / KUNC
Multiple genetic varieties of cannabis are tested at multiple growth stages and in different environmental conditions.

Seré Williams / KUNC
Eaton grows most plants in pots, but these plants are grown in soil to test what they absorb. Cannabis plants are known to take up things that other plants do not (termed "bioremediators") which makes them good at cleaning up the soil.

“Slowly over about three years of time, we had amassed about 286 ‘phenos’ in house, and that’s where we go on what we call the ‘pheno-hunt,’” said Eaton.

The “phenotype” of a plant is how genes express themselves to display observable characteristics. While you can’t see the chemicals in a plant, you can measure them, so high CBD is a desirable phenotype.

But it’s not just about the cannabinoid profile. You have to be able to grow the plant too.

“We have an R&D department where we focus on growth trails first and foremost,” Eaton said. “We’ll do everything from rooting trials, soil density trials, soil nutrition trials, water trials…”

Once you cross the parent plants, you assess the offspring for the best combination of all of these traits. Like the differences between siblings, genetics from the same set of parents will produce an array of phenotypes.

“For instance, I’m going through a CBG genetic right now, and I started 1,400 seeds of that CBG strain. So, I’m in the pheno-hunt of 1,400 plants, which is a crazy task to try to narrow that down to which is the one or two or three mothers that you want to keep,” said Eaton.

But this isn’t just getting the right genetic mix, it’s also about how a grower cares for his plants -- which affects how the genes are expressed. The trick with genes is that they will turn on or turn off depending on the environment.

“That’s what these farmers really need to know,” warned Ted Duerr. “Certain genetics you can’t just let it go to full maturity. Most of the genetics out there will go hot.”

With hemp, if you leave the crop in the field too long or don’t water it on time, the plant can build up too much THC, known as “going hot” in the industry.

“There was some fields that we knew, and they did not water them, and they ended up getting hotter than other fields that I’ve seen,” he said.

Brett Eaton doesn’t know of a hemp variety that makes over 5% CBD that won’t go hot in the field. He only grows plants for cannabinoids in a greenhouse, where he can closely monitor the environmental conditions.

“Don’t go too big.”
Ted Duerr

Some states have asked for a THC variance up to 1% – only 11 Colorado hemp fields would have been destroyed last year had this been the case. The Colorado Department of Agriculture is interested, but they said growers will need to wait for the next farm bill to pass in 2023 before any changes to THC limits come into effect.

Farmers aren’t used to growing hermaphroditic crops that pose a legal threat. So, Duerr has a simple piece of advice for those thinking about growing hemp: “Don’t go too big." He says maybe start with an acre and see how it turns out.

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