Autoflower seeds generally take about 8 to 10 weeks from sprout to harvest. Most modern autoflowering strains finish in roughly 65 to 80 days, while fast varieties can be ready near 60 days and larger sativa-leaning autos may run 90 days or longer. The countdown starts when the seedling breaks the surface, so add two to four days for germination before you mark the calendar.
how long do autoflower seeds take to grow
Key Factors That Shape Autoflower Timing
- Genetics: indica-leaning autos usually finish faster than sativa-leaning ones.
- Germination method: soaking, paper towel, or direct sowing each adds a few days up front.
- Container size: small pots tend to finish sooner, while large pots stretch the cycle.
- Light schedule: 18 to 24 hours of light per day keeps growth steady and predictable.
- Environment: steady warmth with moderate humidity during veg supports faster development.
- Nutrition: light, consistent feeding prevents stalls that push harvest back a week or more.
- Training: gentle low-stress training rarely slows plants, but heavy pruning can.
Materials and Specs
Autoflowering cannabis is created by crossing Cannabis ruderalis into photoperiod genetics, giving plants a fixed internal flowering clock that runs regardless of the light cycle. Feminized autoflower seeds are the most common retail format, and each seed ships as a mature, dried, hand-sorted item. Store them in a cool, dark, dry spot in an airtight container and they stay viable for a year or more. Most growers run autos in 3 to 5 gallon pots under 18/6 or 20/4 light, indoors or out, in mild, well-draining soil mixes.
Cheap Autoflower Seeds Online: Buying Guide for US Growers
Shipping and Returns
Orders are packed discreetly in plain, smell-proof packaging with tracking included. If your seeds arrive damaged or fail to germinate within the recommended window when a documented method is used, contact support for a replacement under the shop guarantee.
Do autoflowers grow faster than photoperiod plants?
Yes. Autos skip the light-cycle trigger entirely, so they flower on a timer and typically finish weeks earlier than photoperiod strains started at the same time.
Can I shorten an autoflower's harvest window?
Only slightly. Steady temperatures, adequate light intensity, and avoiding transplant shock or nutrient stalls keep plants on the fast end of their breeder-stated range.
When should I start counting days?
Start counting from the day the seedling emerges above the soil, not the day you planted the seed. That is the timeline breeders use.