How Long Do Cannabis Seeds Take to Grow?
From seed to harvest, cannabis typically takes 3-6 months depending on the strain type. Autoflowers are fastest at 8-12 weeks, while photoperiods take 14-24+ weeks.
Quick Answer
Seed to harvest timeline (not including drying/curing)
Autoflowers
8-12 weeks
Fastest option for Canadian growers
Photoperiods
14-24+ weeks
Larger yields, more control
Photoperiod Growth Timeline
Photoperiod plants flower based on light schedule changes. Indoor growers control when flowering begins by switching to 12/12 light. Outdoor plants flower naturally as days shorten.
Germination
Seed sprouts and taproot emerges
Seedling
First leaves develop, roots establish
Vegetative
Plant grows in size, no flowers yet
Flowering
Buds develop and mature
Harvest
Cut, trim, and begin drying
Drying/Curing
Dry and cure for best quality
Total: 14-24+ weeks seed to harvest + 2-8 weeks drying/curing
Autoflower Growth Timeline
Autoflowers flower automatically based on age, not light schedule. This makes them faster and ideal for Canadian outdoor grows where the season is short.
Germination
Seed sprouts and taproot emerges
Seedling
First leaves develop quickly
Vegetative
Brief veg period, auto-transitions
Flowering
Flowers automatically, buds mature
Harvest
Cut, trim, and begin drying
Drying/Curing
Dry and cure for best quality
Total: 8-12 weeks seed to harvest + 2-8 weeks drying/curing
Strain Type Comparison
| Strain Type | Seed to Harvest | Total (w/ Cure) | Example |
|---|---|---|---|
| Fast Autoflower | 8-9 weeks | 10-12 weeks | Sour Crack Auto |
| Standard Autoflower | 10-12 weeks | 12-16 weeks | Gorilla Cookies Auto |
| Fast Photoperiod | 12-14 weeks | 14-18 weeks | Northern Lights |
| Standard Photoperiod | 14-18 weeks | 16-22 weeks | Blue Dream |
| Long Flowering Sativa | 18-24 weeks | 20-28 weeks | Haze varieties |
Can Speed Up Growth
- - Choosing fast-finishing autoflower genetics
- - Optimal lighting (18-20 hours for autos)
- - Proper nutrients and pH
- - Ideal temperature (70-85F)
- - Starting with clones instead of seeds
- - Shorter vegetative period (photos)
Can Slow Down Growth
- - Stress from transplanting or training
- - Nutrient deficiencies or overfeeding
- - Temperature extremes
- - Pests or disease
- - Insufficient lighting
- - Sativa-dominant long-flowering genetics
Canada's short growing season is a challenge for outdoor growers. Most regions have frost-free periods from late May to early October - roughly 4-5 months.
Best for Canadian Outdoors
- - Autoflowers (finish before frost)
- - Fast-finishing photoperiods
- - Cold-resistant genetics
- - Indica-dominant strains
Challenging for Canadian Outdoors
- - Long-flowering sativas
- - Tropical genetics
- - Strains needing 12+ weeks flower