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 TELL THAT A FEMALE PLANT HAS BEEN POLLINATED
Pollination of your female cannabis plants will make them produce seeds and spend less energy on producing quality buds. But when you recognise the signs of pollination early, you can avoid putting time and resources into a poor 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.
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.
Of course, growers want to avoid this phenomenon if they’re aiming for the best flowers possible. We’ll dive deeper into what causes hermaphroditism and how to avoid it below.
Despite their differences, all female plants share one thing in common: they produce flowers. These flowers, colloquially known as buds, possess small glandular structures called trichomes that produce cannabinoids such as THC and CBD.
IDENTIFYING EARLY SIGNS OF MALE PLANT
It also means cannabis growers have more control when it comes to crossing specific males and females together. They can choose two healthy and vigorous specimens, place them close together, and produce progeny that express certain traits.
These protruding structures are designed to capture pollen, which leads to fertilisation. They stick out away from the flower to capture pollen from the air, and to await being brushed up against by pollen-covered insects.
The rare hermaphroditic plant contains both female and male sex organs. These plants can sometimes self-pollinate, but this is typically bad as it will create buds with seeds and also pass on hermaphroditic genes.
Cannabis is a dioecious plant, meaning it can be male or female, and the male and female reproductive organs appear on different plants. What’s in your stash jar now are the flowers of a female marijuana plant.
Female plants produce the resin-secreting flower that is trimmed down into the buds you smoke, and males produce pollen sacs near the base of the leaves. Male plants pollinate females to initiate seed production, but the buds we consume come from seedless female plants—these are called “sinsemilla,” meaning “seedless.”
Female marijuana plants
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
Pre-flowers begin to develop four weeks into growth, but they may take a little longer depending on how quickly the sprouting phase occurs. By the sixth week, you should be able to find the pre-flowers and confidently determine the sex of your plant.
Plants originally developed trichomes to protect against predators and the elements. These clear bulbous globes ooze aromatic oils called terpenes as well as therapeutic cannabinoids like THC and CBD. The basis of hash production depends on these trichomes and their potent sugar-like resin.
Cannabis plants show their sex by what grows in between their nodes, where leaves and branches extend from the stalk. Pollen sacs will develop on a male plant to spread seeds and stigma will develop on a female to catch pollen. You can see these differences weeks before they actually start serving their purposes in the reproduction cycle. These are known as “pre-flowers.”