Germination is the process by which a dormant seed takes up water (imbibition), restarts its metabolism and emerges a radicle, the first root. In cannabis the radicle normally appears within 24-72 hours of soaking at warm temperatures, with stragglers out to about a week. The seedling stage begins once the cotyledons open above the surface.
In practice
Growers "germ" or "pop" seeds by soaking them, starting them between damp paper towels, or sowing straight into a plug or the final medium about 5-10 mm (0.2-0.4 in) deep. Warmth matters more than method: around 22-28 °C (72-82 °F) is the comfortable band, and germination slows sharply below about 15 °C (59 °F). Keep the seed moist, not waterlogged; a seed sitting in standing water can run short of oxygen.
A germination rate is a percentage: 48 of 50 seeds showing a radicle is 96%.
Don't confuse with
- Seed viability: whether a seed is alive and able to germinate; germination is the event itself.
- Emergence: the shoot breaking the surface, which comes after germination.
- Sprouting (food): same biology, different purpose; seeds sold for eating are not selected for growing.
