How to store seeds without killing germination.
Mr.GramGram · 10 April 2026 · 3 min read
Cannabis seeds are alive. Inside that cool chitin shell sits an embryo, and it wants as few external stimuli as possible until you plant it. Stored correctly, seeds hold 90%+ germination for five years; stored badly, they drop to 50% inside half a year.
Temperature.
The target is a steady 4–8°C — the bottom shelf of a fridge. Swings are worse than constant warmth: cycling 25→4→25→4 damages the embryo more than a steady 20°C. If the fridge is full, use a dark cupboard with minimal temperature swings.
Humidity.
Seeds need to stay dry — internal moisture around 5–9%. Drop a silica gel sachet (the kind that comes in a shoe box) into a sealed bag or tightly-closing jar, and forget about it for a year. The silica will pull excess moisture and stabilise the microclimate.
Light.
Any light is the enemy. Seeds read light as the signal “time to germinate,” and photons slowly degrade the embryo even through clear plastic. Store in opaque packaging or in a cardboard box inside the bag.
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