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Flowering Stage
Definition: The flowering stage is the reproductive phase of a cannabis plant, when it stops most leafy growth and produces buds covered in resin. Photoperiod plants enter flowering when given 12 hours of uninterrupted darkness daily, and most strains need 7 to 12 weeks to finish. Autoflowers begin flowering on their own based on age.
How Flowering Stage works
Flowering is when the work of veg pays off. The plant redirects energy from leaves and stems into flowers, then into resin, cannabinoids and aroma. The process roughly breaks into three phases.
Week by week
- Weeks 1 to 3, transition: the flowering stretch. Plants grow taller fast and white pistils appear at the tops of branches.
- Weeks 4 to 6, bulking: buds swell and stack, smell intensifies and resin becomes visible.
- Week 7 and later, ripening: pistils darken and curl in, trichomes turn cloudy and lower fan leaves often fade.
Flowering conditions
- Light: 12/12, at 600 to 1,000 PPFD as plants mature.
- Temperature: 68 to 80°F (20 to 27°C), with nights 5 to 10°F cooler.
- Humidity: 40 to 50%, dropping to 35 to 45% in the last two weeks to protect dense buds.
- Nutrients: less nitrogen, more phosphorus and potassium.
Total length depends on genetics. Fast indica-leaning strains finish in about 7 to 8 weeks, while long sativas can run 12 to 14 weeks or more. Strain listings give a flowering time, but the plant, not the calendar, decides the actual harvest window.