The flowering stage for cannabis lasts 6 to 10 weeks for most photoperiod strains and 6 to 8 weeks for autoflowering plants. Indoor growers often plan for 8 to 9 weeks of flowering, while some sativa-dominant varieties can take 11 to 14 weeks. The exact length depends on genetics, environment, and when you start counting.
Typical flowering times by plant type
- Indica-dominant photoperiod: 7 to 9 weeks
- Sativa-dominant photoperiod: 10 to 14 weeks
- Hybrid photoperiod: 8 to 10 weeks
- Autoflowering: 6 to 8 weeks of active flowering, with a total life cycle of 8 to 11 weeks from seed
What counts as the start of flowering
Growers define the start of flowering in two ways. The first is the day you switch to a 12/12 light schedule for photoperiod plants. The second is when the first pistils appear, which can be 1 to 2 weeks after the flip. Breeder estimates often refer to the 12/12 switch, so actual harvest may run a week or two longer.
Factors that change how long flowering lasts
- Genetics: sativa-leaning plants need more time than indica-leaning ones.
- Light schedule: a consistent 12/12 cycle keeps flowering on track; light leaks can slow or stall it.
- Temperature and humidity: cool nights and high humidity can extend ripening.
- Nutrients: too much nitrogen delays flower development; phosphorus and potassium support bud growth.
- Stress: transplanting, pruning, or pests can add days or weeks.
How to tell when flowering is finished
Breeder timelines are a guide, not a guarantee. Check trichomes with a magnifier: clear means immature, cloudy means peak THC, amber means more sedative effects. Also watch pistils recede and calyxes swell. Most growers harvest when 70 to 90 percent of pistils have darkened and trichomes are mostly cloudy.
Cannabis Preflowering Stage: A Guide to Understanding
Convenience and the flowering timeline
Convenience shapes many cannabis choices today. Autoflowering seeds remove the need to change light schedules, and fast-finishing photoperiod strains promise shorter flowering windows. These options suit growers with limited space or time, but they can trade away yield or potency. Matching the flowering length to your setup matters more than chasing the shortest possible harvest.
Cannabis Flower Stretch Stage: Understanding and Maximizing Yield