# How long do autoflowers take from seed to harvest?

> Autoflowers usually take about 9–14 weeks from sprouting to harvest, with fast lines near week 9–10 and long lines near week 13–14. They start flowering at about 3–5 weeks old whatever the light schedule. Add 1–2 weeks of drying before the buds are smokeable. Any setback, such as overwatering, transplanting or hunger, costs time the plant can't recover.

- Canonical: https://genetixbay.com/knowledge/answers/how-long-do-autoflowers-take.html
- Topic: Basics · Type: Numbers
- Evidence: Grower practice · Status: Draft: awaiting expert review
- Full article: [Photoperiod vs autoflower, and how autoflowering is inherited](https://genetixbay.com/knowledge/basics/photoperiod-vs-autoflower.md)
- Also asked as: How long do autos take? | Autoflower total time from seed | When are autos ready? | How many weeks is an autoflower?
- 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

[Autoflowers](https://genetixbay.com/knowledge/glossary/autoflower.md) take about 9–14 weeks from [sprouting](https://genetixbay.com/knowledge/glossary/germination.md) to harvest. Fast lines finish near week 9–10, long lines near week 13–14, and the light schedule doesn't change that. Add 7–14 days of drying. *Grower practice* for the durations; the age-based flowering behind them is *Supported* genetics.

## Why

An autoflower is day-neutral. It carries two copies of a [recessive allele](https://genetixbay.com/knowledge/glossary/recessive.md) at a mapped [locus](https://genetixbay.com/knowledge/glossary/locus.md), *Autoflower1*, so it flowers by age rather than by night length [1]. [Gene](https://genetixbay.com/knowledge/glossary/gene.md) dosage at that locus shifts flowering time and height, which is part of why lines differ by weeks [2].

The clock starts at germination and doesn't stop. A [photoperiod plant](https://genetixbay.com/knowledge/glossary/photoperiod.md) can stay in veg until it recovers from a mistake. An auto flowers on schedule whether it has recovered or not, so a setback costs size, and often a few days on the finish, never a longer [harvest window](https://genetixbay.com/knowledge/glossary/harvest-window.md) you can use. That's the GenetixBay house position: any setback costs an auto.

More light means more growth in the same time, not an earlier finish. Yield rose with light in a controlled trial [3]; autos on 18–20 h get 1.5–1.7× the daily light of 12 h at the same intensity.

## The numbers

| Week from sprouting | What's happening |
|---|---|
| 1–2 | Seedling, [first true leaves](https://genetixbay.com/knowledge/glossary/true-leaves.md) |
| 3–4 | Fast veg; [preflowers](https://genetixbay.com/knowledge/glossary/pre-flower.md) appear |
| 3–5 | [Pistils](https://genetixbay.com/knowledge/glossary/pistil.md) at the main tip: flowering starts |
| 5–7 | [Stretch](https://genetixbay.com/knowledge/glossary/stretch.md), early flower |
| 8–10 | Bulking |
| 9–14 | Ripening and harvest, by [trichomes](https://genetixbay.com/knowledge/glossary/trichome.md) |
| +1–2 | Drying |

## What to do

1. Plan the space for 14 weeks, and be pleased if it's 10.
2. Sow straight into the final pot; don't [transplant](https://genetixbay.com/knowledge/glossary/transplanting.md).
3. Run one schedule throughout: [18/6](https://genetixbay.com/knowledge/glossary/18-6.md), 20/4 or 24/0.
4. From about week 8, check trichomes every 2–3 days.
5. Harvest at a few clear, mostly cloudy, some amber heads.

## Common mistakes

- Harvesting on the breeder's week count instead of the trichomes.
- Switching an auto to [12/12](https://genetixbay.com/knowledge/glossary/12-12.md) "to speed it up". It doesn't; it only cuts light.
- Starting in a cup and transplanting, which stalls the plant while the clock runs.
- Assuming every seed in an auto pack is a true auto. Poorly [stabilised lines](https://genetixbay.com/knowledge/glossary/ibl.md) throw photoperiods.

## Related

- Full article: [Photoperiod vs autoflower](https://genetixbay.com/knowledge/basics/photoperiod-vs-autoflower.md)
- Guide: [Autoflower first grow, week by week](https://genetixbay.com/knowledge/guides/autoflower-first-grow-week-by-week.md)
- Answers: [when autos start flowering](https://genetixbay.com/knowledge/answers/when-do-autoflowers-start-flowering.md) · [why my auto is small](https://genetixbay.com/knowledge/answers/why-is-my-autoflower-small.md) · [checking trichomes](https://genetixbay.com/knowledge/answers/how-to-check-trichomes.md)
- Terms: [autoflower](https://genetixbay.com/knowledge/glossary/autoflower.md)

## Follow-up questions

**Do autoflowers finish faster on 24 hours of light?** No, autoflowers do not finish faster on more hours of light. They flower by age, so 18/6, 20/4 or 24/0 give roughly the same 9–14 week timeline. Longer days add daily light: at the same intensity, 18–20 hours gives about 1.5–1.7 times the light of 12 hours, which means more growth in the same number of days, not an earlier harvest.

**Why is my auto taking longer than the breeder says?** An autoflower usually runs past the breeder's stated time because of genetics, setbacks or optimistic marketing. Stress early in the grow slows growth without stopping the flowering clock, and some 'autos' are poorly stabilised lines. Breeder times are claims, so plan for 9–14 weeks and decide the harvest day by trichomes, not the calendar.

**How long does it take to grow an autoflower start to finish?** An autoflower takes about 9–14 weeks from seed to harvest, then roughly 7–14 days of drying and at least two weeks of curing for good flavour. Allow about 3–4 months from planting to a cured jar. A photoperiod plant grown indoors from seed usually takes about 3–5 months before drying.

## Sources

1. Toth JA, Stack GM, Carlson CH, Smart LB. 2022. Identification and mapping of major-effect flowering time loci Autoflower1 and Early1 in Cannabis sativa L. Frontiers in Plant Science 13:991680. https://doi.org/10.3389/fpls.2022.991680
2. Kurtz LE, Brand MH, Lubell-Brand JD. 2023. Gene dosage at the autoflowering locus effects flowering timing and plant height in triploid cannabis. Journal of the American Society for Horticultural Science 148(2):83-88. https://doi.org/10.21273/JASHS05293-23
3. Rodriguez-Morrison V, Llewellyn D, Zheng Y. 2021. Cannabis yield, potency, and leaf photosynthesis respond differently to increasing light levels in an indoor environment. Frontiers in Plant Science 12:646020. https://doi.org/10.3389/fpls.2021.646020