Harvest Date Calculator
Enter your germination date, seed type and flowering time to see when your plants should be ready, then confirm with the trichomes.
Autoflower vs photoperiod timelines
Typical ranges. Photoperiod flowering time counts from the switch to 12/12. Autoflower times usually count from germination.
| Stage | Autoflower | Photoperiod (indoor) |
|---|---|---|
| Germination and seedling | 1-2 weeks | 1-2 weeks |
| Vegetative growth | 2-4 weeks, set by genetics | 3-8 weeks, you decide |
| Flowering | 5-8 weeks, starts on its own | 7-10 weeks for most indicas and hybrids, 10-14 for sativas |
| Seed to harvest | 8-12 weeks | About 11-24 weeks |
| Drying | 7-14 days | 7-14 days |
| Curing | 2-4 weeks or longer | 2-4 weeks or longer |
Reading trichomes: the final word on harvest
Dates get you close. Trichomes tell you when to cut. These tiny resin glands change color as the plant matures, and you can see them clearly with a 30x to 60x jeweler’s loupe or an inexpensive digital microscope.
- Clear: glassy and see-through. The buds aren’t ready yet.
- Cloudy (milky): most growers treat this as peak maturity. Harvest when the majority of trichomes look cloudy.
- Amber: cloudy heads slowly turn gold. Many growers wait for about 10 to 30 percent amber, which consumers commonly describe as a heavier, more relaxing effect.
Check the buds themselves, not the sugar leaves, which tend to amber sooner. Look at several buds from the top and middle of the plant, since top colas often mature first. Pistils turning brown is a rougher sign and can mislead, so use it only as a cue to start checking. Our entry on the harvest window goes deeper.
Outdoor photoperiods follow the season
Outdoors, photoperiod plants start flowering when nights lengthen in late July or August, no matter when you planted them. Most indicas and hybrids finish between mid September and mid October in the northern US, while sativas often run into late October or November. For outdoor photoperiods, use the calculator as a check against your first frost date, and see when to plant outdoors for regional timing. After the chop, follow our harvest, dry and cure guide.
Harvest timing FAQ
How do I know when my plant is ready to harvest?
Check the trichomes with a loupe. When most look cloudy and a few have turned amber, the plant is at or near peak. Calendar dates and the breeder's flowering time tell you when to start checking, usually a week or two before the expected finish.
How long do autoflowers take to harvest?
Most autoflowers are ready 8 to 12 weeks after germination, and some larger strains take up to 14 weeks. Light schedule, pot size and stress can shift that by a week or more. Start checking trichomes around week 8 for fast strains and week 10 for larger ones.
When does flowering time start counting?
For photoperiod strains, breeders count flowering time from the day you switch the lights to 12/12. For autoflowers, the listed time usually covers the whole life cycle from germination. Some breeders count differently, so read each listing, and enter the weeks that match how it was counted.
What happens if I harvest too early or too late?
Harvesting early, with mostly clear trichomes, usually means lighter buds and weaker effects. Harvesting late, with mostly amber trichomes, is commonly reported to feel heavier and sleepier, and it risks lost aroma and mold. Most growers aim for mostly cloudy trichomes with a little amber.
Should I flush before harvest?
Want a harvest in about three months?
Autoflowers go from seed to harvest in roughly 8 to 12 weeks with no light schedule change.