Knowing how to spot male and hermaphrodite plants is essential to producing a high-value organic CBD crop. Unless you're a breeder or growing hemp for seed, the goal of the artisanal hemp grower is to nurture and protect the unpollinated female plants. The males have only one thing on their mind, and your job is to keep them off the farm.
Growing outdoors in the Northeast, Cannabis first goes through a pre-flowering stage sometime in July. (You can learn more about the timing of the different stages of growth, in our previous article). If this is your first year, suspense can mix with the thrill of what's to come when flowering starts, especially if you're managing a large operation.
Your mission is to keep calm, carry on, and know how to identify hemp's reproductive organs. This article will show you how, and in just one season you'll be a pro at finding (and eradicating) the males.
Most plants of the Cannabis species are dioecious, meaning they produce either male or female reproductive organs. Thus a male plant pollinates a female plant, turning her flowers to seed for next year's crop.
In some cases, pollination can occur on a monoecious plant that displays both male and female flowers. If all else fails, cannabis has evolved to produce a hermaphrodite; with both male and female sex organs on the same flower.
How To Identify Male Vs. Female Cannabis (Hemp) Plants
About six weeks into the "Vege" stage, the moment of truth has arrived, and the plants begin to declare their sex. You'll want to pay close attention as the pre-flowers start to develop at the nodes; the places where the leaves and branches extend along the central stalk. The pre-flowers are difficult to see with the naked eye, so a great tool to have on hand is a jeweler's loupe or magnifier.
But how do you know if it's a male or a female?
When you examine the nodes of the plant, what you're looking for are the development of bracts (female) that will produce hair-like stigma, or else tiny grape-like sacs or balls (yup, male for sure) and these will produce pollen if allowed to develop.
Once you've spotted a pre-flower, sometimes it's hard to be sure at first whether it's male or female. In most cultivars (or "strains") - males will typically declare their gender before the females. But you don't want to guess and yank up a female by mistake. If you're not sure, flag the plant and wait a few more days and see if white hairs appear. Now you know it's a girl.
Don't worry if you miss catching all the males at this stage, within another week or two when the first true flowers appear, you'll have no problem telling the boys from the girls. But by then, you must take quick action to remove the male plants and avoid pollination.
Beware the Hermaphrodites
It's going to happen one day; you'll discover one or more branches on a female in full flower has also developed male pollen sacs. You now have a hermaphrodite on your hands, and it's not good. A hermaphrodite plant is not only capable of pollinating itself, but it's going to pollinate everything around it if you don't cut it down.
Why does a female in full bloom turn hermaphrodite? Sometimes it's poor genetics, but more often, the change occurs due to excessive stress. Some of the likely stressors include:
- Plant damage
- Bad weather
- Nutrient deficiencies
Because hermaphrodites often develop after female flowering is underway, it's necessary to scout your rows carefully and more than once.
Train Your Team and Scout Your Rows
If you're a home gardener with a few hemp plants, it's one thing to protect your females from unwanted sex. But if this is your livelihood, and you have 10,000 or 100,000 or more plants under your care, you'll need to stay vigilant for up to 4-5 weeks.
Many growers at this scale start their crop with feminized seeds. The pros and cons of using feminized seed are beyond the scope of this article; however, you can follow some of the discussion here and here.
If you're starting with quality feminized seed genetics, keep in mind that for every 1,000 plants you should still expect anywhere from 5 to 10 (or more) to be male. Plus, there are going to be hermaphrodites, so there's still the potential for a helluva lot of pollen if you let your guard down.
To sum up:
- Learn to identify males, females, and hermaphrodite hemp plants.
- Know when to start scouting and eradicate the males as soon as you can.
- Be on the lookout for hermaphrodites, and stay vigilant as the season progresses.
Keep up the good work! It won't be long until the trichomes glisten, and the fragrant terpenes mingle on a warm summer's eve.
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