A good test to see whether the bracts have swollen is to take a pair of tweezers, grab one bract, and open it up. If there is a seed inside, you have a pollinated plant.
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.
HOW TO AVOID POLLINATION OF YOUR FEMALE PLANTS
Another indication of pollination can be the colour of her pistil hairs. When a female has been pollinated, the previously white hairs will soon shrivel and become darker.
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.
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.
Female plants usually take several days longer than males to develop pistils or female sexual organs. The pistils look like small green seed pods and have white v-shaped stigmas, or thin hairs, which extend from them. Female plants are generally shorter, denser in foliage, and broader than their male counterparts.
When female plants herm, or develop male flowers capable of disseminating pollen, the entire crop is at risk of pollination. Female flowers that have been fertilized by pollen will halt their development to produce seeds, limiting flower production.
“When you see a pollen sac, you will know that a female plant is turning male,” says Perlowin. “Oftentimes, you can tell before the pollen sack becomes a problem. You should examine the plant from the very bottom of the plant to the top. It is easy to spot when the pollen sacs are at the top of the plant, but be sure to examine if there are pollen sacs at the bottom.” Male plants additionally grow taller than female plants as they mature and have thicker stems and fewer leaves.
Can you turn a male plant female?
Other stressors that may incite female cannabis plants to become hermaphroditic include disruptions to the photoperiod, dramatic shifts in temperature, disease or pest infestations, the use of toxic pesticides, and physical damage from vigorous pruning.
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 .
Cannabis plants are gendered, or for the botanically-inclined, dioecious. Female plants are particularly prized because they form buds that are rich in cannabinoid content. For most growers, maintaining a crop free of male plants is critical to ensuring that female buds are not pollinated.
Female plants are generally shorter, denser in foliage, and broader than their male counterparts. Photo by: Gina Coleman/Weedmaps