Feminized Seeds
Definition: Feminized seeds are cannabis seeds bred to grow into female plants, which produce the resinous buds growers harvest. Breeders make them by treating a female plant so it forms pollen sacs, then using that pollen on another female. Because the pollen carries no Y chromosome, well-made feminized seeds produce females in roughly 99% of cases.
How Feminized Seeds works
Cannabis plants are usually either male or female, with an XY sex system much like ours. Only unpollinated females form the large, seedless flowers called sinsemilla. With regular seeds, about half the plants turn out male and must be found and removed. Feminized seeds remove that guesswork.
How feminization works
Breeders spray a selected female with a solution that blocks ethylene, most often silver thiosulfate (STS) or colloidal silver. The treated branches grow male pollen sacs, but the pollen carries only female (XX) genetics. Pollinating a second female with it yields seeds that grow into females.
What feminized seeds mean for your grow
- Every seed you pop is a potential harvest, so you can plan plant counts precisely.
- No sexing step, so you never spend 4 to 6 weeks feeding and lighting plants that turn out male.
- Stress can still cause a few hermaphrodite flowers, especially with light leaks or heat above 85°F (29°C), so inspect plants weekly in early flower.
Feminized seeds can be photoperiod or autoflower. For breeding your own strains, though, you still need males, which only regular seeds provide.