How to Tell If Your Cannabis Seeds Are Still Good

Before you burn a week waiting for a seed to germinate, five quick checks will tell you whether it's worth dropping in water or you're better off tossing it and cracking open another. Three are visual, one is by touch, one is the float test. Anyone can run all five in 5 minutes.

1. Color

A good seed is dark brown, or brown with darker tiger stripes. Some strains run almost black or carry dark green tones — that's normal too. What's NOT normal:

• Pale green or white: immature, harvested too early, won't germinate.
• Pale gray or yellowish: old or badly stored — the odds are very low.
• Irregular dark blotches (a stain, not stripes): possible fungus.

2. Firmness

Squeeze it gently between two fingers. It should hold up under pressure without collapsing. If it crushes, it's hollow or dried out inside — it won't germinate. A viable seed feels firm, almost like a tiny stone.

3. Shape and size

Viable seeds are oval, symmetrical, with a full "belly". If it's misshapen, or way too small or too big for its strain, odds are it has some developmental issue. Not an absolute rule, but combined with the other checks it tells you plenty.

4. Age

A well-stored seed (airtight jar, dark, fridge at 5-10°C / 41-50°F, low humidity) can stay viable for 3-5 years. Badly stored (a drawer at room temperature, exposed to light or heat) drops to 6-12 months. If you don't know the date, go by color and firmness: an old seed looks and feels old.

5. The float test

If the four checks above came back clean, run the final test: a glass of lukewarm water (25°C / 77°F, not hot). Drop the seed in. Within 1-2 hours:

• It sinks and stays on the bottom: viable, go ahead and germinate it.
• It floats, but after a nudge with your finger it sinks and stays down: viable.
• It floats and keeps floating, even after 4 hours: empty or dead. Toss it.

A seed that passes all five checks has an 80-95% chance of germinating well. If it still fails, the seed is almost never the problem: it's usually a waterlogged medium, badly managed temperature, or a substrate packed too tight.

If you buy seeds, buy from someone who can give you a harvest date and a tested germination rate. At our club's seed bank in Argentina, every seed ships with both printed on the label.