# How long does the flowering stage take?

> Most photoperiod cannabis flowers for about 7–10 weeks, counted from the first pistil clusters, but harvest comes about 9–12 weeks after the flip, because the flip isn't day 1 of flower: a 10–14 day transition comes first. A breeder's '8 weeks' usually means harvest about 9.5–10 weeks after switching to 12/12. Long-flowering equatorial types can take 11–16 weeks or more.

- Canonical: https://genetixbay.com/knowledge/answers/how-long-does-flowering-take.html
- Topic: Environment · Type: Numbers
- Evidence: Supported · Status: Draft: awaiting expert review
- Full article: [The flip isn't day 1 of flower: the 10–14 day transition and how to count it](https://genetixbay.com/knowledge/environment/flip-to-flower-transition.md)
- Also asked as: How many weeks does cannabis take to flower? | How long from the flip to harvest? | Indoor flowering time for photoperiod plants | Why is my plant taking longer than the breeder said?
- Updated: 2026-10-31 · Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay Knowledge Base (genetixbay.com/knowledge)"

## Short answer

Most [photoperiod](https://genetixbay.com/knowledge/glossary/photoperiod.md) cannabis flowers for about **7–10 weeks** counted from the first [pistil](https://genetixbay.com/knowledge/glossary/pistil.md) clusters, so harvest lands about **9–12 weeks after the flip**. **House position: the flip isn't day 1 of flower.** A transition of about **10–14 days** comes first, so a breeder's "8 weeks" usually means harvest **9.5–10 weeks** after switching to [12/12](https://genetixbay.com/knowledge/glossary/12-12.md). *Supported*.

## Why

Switching to long nights starts floral induction, not flowering. The [shoot tip](https://genetixbay.com/knowledge/glossary/apical-meristem.md) spends the next week or two rebuilding itself. In controlled studies, the first proper pistil clusters at the top of the main shoot appeared about 8–14 days after short days began [1][2]. Across 27 [hemp cultivars](https://genetixbay.com/knowledge/glossary/hemp.md) the average was 13–14 days, and slow ones took three weeks [2].

Many breeders count flowering time from that point ("flower set"), not from the flip. That's why most runs seem to go about two weeks long.

Flower length itself is genetic. Indoor medical [genotypes](https://genetixbay.com/knowledge/glossary/genotype.md) typically run 7–14 weeks of flowering [4]; equatorial types run longer.

A [13/11](https://genetixbay.com/knowledge/glossary/13-11.md) schedule barely changes the clock: about 1.5 days later onset in one cultivar, none in another, with more yield [3].

## The numbers

| Plant type | Weeks of flower | Weeks from flip to harvest |
|---|---|---|
| Fast indica-leaning hybrid | 7–8 | ~9–10 |
| Typical hybrid | 8–10 | ~10–12 |
| Long equatorial type | 11–16+ | ~13–18+ |
| Transition (flip to first pistil clusters) | — | 10–14 days typical; up to 3 weeks |
| Breeder's "8 weeks" | 56 days | 66–70 days |

## What to do

1. Log two dates: the flip, and the first 3+ pairs of pistils at the top of the main shoot.
2. Add 10–14 days to any breeder's stated time.
3. Plan the room on the longer figure.
4. Start [trichome](https://genetixbay.com/knowledge/glossary/trichome.md) checks about two weeks before the expected finish.
5. Harvest on trichomes, mostly cloudy with some amber to taste, not the calendar.

## Common mistakes

- Counting the flip as day 1 and harvesting two weeks early.
- Calling veg [preflowers](https://genetixbay.com/knowledge/glossary/pre-flower.md) "flowering".
- [Light leaks](https://genetixbay.com/knowledge/glossary/light-leak.md) in the first two weeks, stalling induction.
- Judging ripeness by pistil colour alone.

## Related

- Full article: [The flip isn't day 1 of flower](https://genetixbay.com/knowledge/environment/flip-to-flower-transition.md)
- [When should I flip my plants to flower?](https://genetixbay.com/knowledge/answers/when-to-flip-to-flower.md)
- [In which weeks of flower do buds grow the most?](https://genetixbay.com/knowledge/answers/when-do-buds-grow-the-most.md)
- [How do I check trichomes?](https://genetixbay.com/knowledge/answers/how-to-check-trichomes.md)
- Terms: [flowering stage](https://genetixbay.com/knowledge/glossary/flowering-stage.md) · [flip](https://genetixbay.com/knowledge/glossary/flip.md)

## Follow-up questions

**How long after the flip to harvest?** Most photoperiod cannabis is ready about 9–12 weeks after the flip to 12/12: a transition of roughly 10–14 days before the first pistil clusters, then 7–10 weeks of flower for typical hybrids. Long-flowering equatorial cultivars can need 13–18 weeks from the flip. Decide the actual day by trichomes, mostly cloudy with some amber to taste, not by the calendar.

**Why does my strain take longer than the breeder says?** A cannabis strain usually takes longer than the breeder's stated flowering time because many breeders count from flower set, the first visible pistil clusters, not from the flip. The 10–14 day transition gets added on top, so a stated 8 weeks typically means harvest about 9.5–10 weeks after switching to 12/12. Count both clocks in your journal.

**Does 13/11 make flowering take longer?** A 13/11 photoperiod adds very little to cannabis flowering time: in one study of two THC-dominant cultivars, 13 hours delayed flowering onset by about 1.5 days in one and not at all in the other, while yield rose 1.35× and 1.5×. GenetixBay endorses 13/11. Sensitive cultivars may need a day or two more, so test your own.

**How long do autoflowers take?** Autoflowers don't follow the flip-to-harvest clock, because the photoperiod doesn't trigger their flowering. Most run about 9–14 weeks from germination to harvest on 18/6 to 20/4 light, starting to flower on their own after a few weeks of growth. Any setback costs an autoflower time it can't win back, so plant it straight in its final pot.

## Sources

1. Spitzer-Rimon B, Duchin S, Bernstein N, Kamenetsky R. 2019. Architecture and florogenesis in female Cannabis sativa plants. Frontiers in Plant Science 10:350. https://doi.org/10.3389/fpls.2019.00350
2. Zhang M, Anderson SL, Brym ZT, Pearson BJ. 2021. Photoperiodic flowering response of essential oil, grain, and fiber hemp (Cannabis sativa L.) cultivars. Frontiers in Plant Science 12:694153. https://doi.org/10.3389/fpls.2021.694153
3. Ahrens A, Llewellyn D, Zheng Y. 2024. Longer photoperiod substantially increases indoor-grown cannabis' yield and quality. Plants 13(3):433. https://doi.org/10.3390/plants13030433
4. Crispim Massuela D, Hartung J, Munz S, Erpenbach F, Graeff-Hönninger S, 2022. Impact of harvest time and pruning technique on total CBD concentration and yield of medicinal cannabis. Plants 11(1):140. https://doi.org/10.3390/plants11010140