Français Autoflowering and feminized are two different things
An autoflowering plant switches from growing leaves to flowering based on its age rather than the length of daylight. The trait comes from Cannabis ruderalis, a hardy plant from cold regions of Russia, Central Europe and Central Asia, and many autoflowers can be harvested within about 10 weeks of planting. A feminized seed is something else: it has been bred so that the plants it grows are female.
Because the two traits are independent, a seed can be one, both or neither:
| Seed type | When it flowers | Male plants? |
|---|---|---|
| Regular photoperiod | When the light cycle changes | About half of the plants |
| Feminized photoperiod | When the light cycle changes | Very unlikely |
| Regular autoflower | With age | About half of the plants |
| Feminized autoflower | With age | Very unlikely |
The “about half” figure comes from research on cross-fertilized cannabis, which gave roughly one male for every female seedling (see Sources).
Why most autoflower seeds are feminized
Growers want the female plants, because they grow the flowers (buds) that get harvested, while male plants make pollen. A pollinated female puts energy into seed instead, which is why a male in the room can ruin a crop. For that reason most autoflower seeds sold today are feminized, and only a few brands offer regular ones. If you only want to grow for flower, choose feminized. If you are curious why a feminized plant can still end up with seeds, read Do feminized cannabis plants produce seeds?
What if a feminized autoflower grows pollen sacs?
It is uncommon, but it can happen. Research on hermaphrodite cannabis found that these flowers develop anthers that make pollen much like a male flower, and that they can produce viable seed. The authors describe the mechanism behind this as poorly understood, so no breeder can promise a zero percent chance. In practice, check your plants regularly once they start to flower, and if you find pollen sacs, move that plant away from the others before it releases pollen.
Can you tell the sex of a seed?
Not by looking at it. A seed shows its sex only once the plant develops, which is why buying seeds that are clearly labelled feminized is the simplest way to avoid males. Browse our autoflower cannabis seeds, or read what autoflowering seeds are and how long the flowering stage lasts.
Frequently asked questions
Are all autoflowering seeds feminized?
No. Most autoflower seeds sold today are feminized, but regular autoflower seeds exist and they grow both male and female plants. Always check that the product name or description says feminized.
Can an autoflower seed grow into a male plant?
A regular autoflower seed can, and about half of the plants will be male. A feminized autoflower seed is bred to grow female plants, so males are very unlikely, although a plant can occasionally develop pollen sacs.
Do autoflowers need a 12/12 light schedule to flower?
No. Autoflowers flower with age rather than with the light cycle, so they do not need the light schedule to change.
How long do autoflowers take from seed to harvest?
Many are ready within about 10 weeks of planting, and our own guide puts most strains at around 10 to 12 weeks from seed. It depends on the strain and the grow conditions.
Will a feminized autoflower produce seeds?
Only if it is pollinated or develops pollen sacs and pollinates itself. Without pollen, a feminized autoflower grows seedless flower.
Sources
- Autoflowering cannabis (Wikipedia): age-based flowering, ruderalis origin, and most autoflower seeds being feminized.
- Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences, Frontiers in Plant Science, 2020: hermaphrodite flowers, viable seed and progeny sex ratios.
General information, not medical or legal advice.
