Growers can ensure the sex of their plants by growing clones or the genetically identical clippings from a parent strain. Feminized seeds are also made available through a special breeding process.
However, cannabis is primarily cultivated for buds, not seeds, so the practice of growing sinsemilla, or “seedless” cannabis, is prevalent today: Females and males are grown separately, or males are even discarded, to prevent pollination. This allows female plants to focus their energies on bud production instead of seed production.
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.
Stigma and pistil
Despite their minute size, it’s hard to miss the blanket of crystal resin on a cannabis bud. This resin is secreted through translucent, mushroom-shaped glands on the leaves, stems, and calyxes.
Males and females are usually only pollinated when crossbreeding plants or creating new strains.
The space between nodes is called “internodal spacing” and will give you a sense of whether a plant will grow tall or short.
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.
Take four sheets of paper towels and soak them with distilled water. The towels should be soaked but shouldn’t have excess water running off.
One drawback of clones is they need to be taken during the vegetative stage of a plant—flower is too late—so if you have a small setup with only one light, it can be hard to keep clones alive while flowering other plants, because the two need different amounts of light.
Cultivating males is important for breeders trying to cross new strains and genetics, but most people growing for buds will want to remove the males.
How to germinate marijuana seeds
Remember, once a seed germinates, the real work begins. Sexing, selecting, vegetative growth, flowering, and the eventual harvest all lie ahead.
One way to avoid sexing plants is to buy feminized seeds (more below), which ensures every seed you plant will be a bud-producing female.
Also, autoflower plants are small—perfect for closet grows or any small grow, or growing outdoors where you don’t want your neighbors to see what you’re up to.
Once cannabis seeds are mature, the female plant begins to die, and seeds are either dropped to the ground where they grow into new cannabis plants next spring, or the seeds are harvested for processing into seed oil or food products, or stored so they can be sown in the ground later and become the next generation of plants.