Removing or ‘rogueing’ male industrial hemp plants in your industrial hemp biomass production is a critical part of the growing process.
Cannabis is a dioecious species. Which means it has separate female and male plants. If you are growing for hemp fiber or hemp seed, this isn’t a problem. For industrial hemp grown for CBD biomass, however, the male hemp plants pose several issues.
The majority of high percentage hemp CBD resin is produced in the trichomes of the unpollinated ‘flower’ of the female plants. Males don’t produce flowers, so it is a waste to put growing space toward them.
But it’s more than that. A male will pollinate and greatly reduce the value of your high CBD hemp seed genetics. Once pollinated, female cannabis plants put their energy into seed production, reducing their cannabinoid value by 50 percent or more over unpollinated ‘virgin’ flowers.
Ideally, hemp CBD growers reduce the amount of male versus female plant in their production by buying certified feminized hemp seeds. Feminized hemp seeds can theoretically produce nearly 100 percent female plants.
However, even with the feminized hemp seed, nature can find a way to prevail. And what nature most wants to do is… reproduce!
Males and female plants will start to show their ‘sex,’ aka pre-flowers, anywhere from the second to fifth week of vegetative stage. They are usually first observed at about the fourth set of leaves up, right at the branching nodule.
A female plant will produce ‘pistils’ which appear as small, thread-like white hairs. Males have (literally) ‘balls’ or pollen sack, that look like little green, grape-like clusters.
The male plants will often grow taller than the female plants. The female plants tend to stay shorter and bushier. Biologically speaking, the male plants are working hard to stretch tall, so they can disperse their ‘genetics’ widely and impregnate lots of their hemp-girlfriends!
Walk your fields every few days to check for males as they start to ‘show signs’ of their sex. Train your crew on it if you have workers weeding your crop. But make sure they are CLEAR what a male versus a female plant. Avoid the catastrophe of a confused employee pulling up the girls instead of the boys!
If there is any question, have them flag questionable plants and you can always come back to make the final call.
The cannabis plant has the ability, when stressed, to produce ‘hermaphrodites.’ Or individual plants that have both female flowers AND male pollen sacks. This is typically when plants are stressed, more often seen in greenhouse conditions. But ‘hermies’ can ruin a crop just as quick as a male plant.
So, get out there and walk those fields!