Autoflower
Definition: An autoflower is a cannabis plant that switches from vegetative growth to flowering based on age instead of light schedule, a trait inherited from ruderalis genetics. Most autoflowers go from seed to harvest in 8 to 12 weeks, stay 2 to 4 feet tall, and can run under the same light hours from start to finish.
How Autoflower works
Photoperiod cannabis waits for long nights before it flowers. An autoflower ignores the clock. Around week 3 to 5 from sprout it shows pre-flowers, and by week 5 or 6 it is building buds no matter how many hours of light it gets. Most indoor growers run autos on 18/6 or 20/4 for the whole life cycle.
A typical autoflower timeline
- Weeks 1 to 2: seedling stage, slow on top while roots establish.
- Weeks 3 to 5: rapid vegetative growth and the start of flowering.
- Weeks 6 to 11: bud development and ripening; check trichomes from week 8.
Rules that keep autos happy
Because the vegetative window is short, every stress costs yield. Sow directly into the final pot (3 to 5 gallons is plenty) to skip transplant shock. Use low-stress training rather than late topping or high-stress training. Keep early feeding light, since young autos burn easily.
The payoff is speed and simplicity. Outdoors, autos can finish in midsummer, ahead of the fall mold season, and small, stealthy plants suit balconies. Indoors, you can harvest several runs a year with no light-flip planning. The trade-off is lower yield per plant than a well-vegged photoperiod.