The typical cannabis grower normally doesn’t have a reason to keep males, and will want to get rid of them as soon as they are spotted. Cannabis breeders, on the other hand, may want to keep males along with their crop of female plants. In such cases, the breeder will normally separate the sexes to avoid any accidental pollination. They may grow females in one tent and males in another. When grown outdoors, such as in a garden, the males are often kept in the most remote corner of their growing area, as far from the females as possible. Even then, because of the wind carrying around the pollen, there is always some risk of accidental pollination.
There is a good reason why most growers keep male plants away from their ladies: Pollination from males causes the females to develop seeds. As a result, females focus their energy on seed production, rather than on growing you some fine-quality bud. This seedy and unfortunate final product can be avoided by implementing a few basic techniques.
To determine the sex of your cannabis plants, you will have to wait until the pre-flowering stage when plants begin to put their energy into reproduction. Female cannabis plants show their gender signs later than males. At the location where they will soon grow their buds (the nodes between the stalk and the stem), females will show wispy white hairs.
HOW TO SPOT MALE CANNABIS PLANTS
Male plants won’t show hairs at these nodes, but will develop little sacs of pollen. These pollen sacs will look like little balls. These balls can appear on their own or in clusters, depending how far into the pre-flowering stage the plant is. At some later stage of growth, the pollen sacs will burst open, spilling the pollen and possibly pollinating your females.
Among the early signs that your female has been pollinated is that her bracts become larger. Bracts are small, leaf-like structures that protect the female’s reproductive parts. These are the sites from which the flowering buds appear. Do not confuse the bracts with calyxes.
Obviously, no one wants to smoke seedy weed. When you grow cannabis and learn how to identify male plants and signs of pollination, you can remove these plants to save your remaining females. Likewise, recognising a pollinated female early allows you to start again before it’s too late, rather than finishing a grow that will only result in a poor-quality harvest.
Pollination requires the presence of males or intersex (hermaphrodite) plants, which are females that will also produce pollen. The first thing you want to do to keep the risk of pollination low is to remove as many males or “hermies” as as you can. Especially during the first three weeks of flowering, it’s important to frequently check for possible male specimens in your garden.
Herming can occur when female plants experience conditions of environmental stress. “Female plants don’t actually turn male, they become hermaphrodites,” says Bruce Perlowin , CEO of Hemp, Inc . and seasoned cannabis cultivator. “You have a female plant that develops both reproductive parts so it can pollinate itself.” A hermaphroditic plant, by definition, contains both female and male sex organs .
Elevated levels of female hormones in male cannabis plants can trigger female flowering development. The technique is more effective when applied to male plants that have not yet formed mature flowers. It’s also vital to bear in mind that many male marijuana plants are hermaphroditic plants, and distinguishing true males can be very difficult.
What is herming, and why does it happen?
The sex of a plant is determined by its genetics before germination even begins. With the sex genetically encoded, there is no way to make a male plant female, or a female plant male. There are techniques that can be used, however, to encourage a male plant to display female characteristics. These techniques require the use of chemicals, such as ethylene , to prompt a hormonal response from the plant.
“Herming can also definitely be a genetic problem, but it is not cultivar-specific,” says Perlowin. “You can get the same cultivars from different seed companies, and they will yield different results.” Reputable breeders are more likely to competently sort and select seeds from genetically robust plants with desirable traits.
To a non-expert grower, all cannabis seeds look alike. The gender of cannabis plants becomes more readily apparent when the plant approaches the flowering period .