To test seed, lay 10 on a damp paper towel, fold it, seal it in a bag or covered container, keep it warm at about 20 to 25 C, check daily, and count how many have sprouted after 3 to 14 days depending on the species. Eight or more out of 10 is excellent, and fewer means you must sow more seed per plant you want. Test before you plant seed you cannot replace.
Part of Seed & Food Salvage
A germination test shows whether seed is alive before you commit it to soil where failure cannot be seen. The steps follow the parent article, and the sowing arithmetic is corrected here.
Test Where You Can See, Before You Plant Where You Cannot
In soil you cannot see whether a seed has failed. On a towel you can. The parent article recommends testing before committing seeds to the ground.
What You Need
- Paper towel or cloth, a ziplock bag or covered container to keep moisture in.
- 10 seeds of the kind you are testing.
- A warm place, 20 to 25 C (70 to 80 F): near a stove, a sunny window, or the top of a water heater.
- A pen and notes, for species, date and result.
Method: Ten Seeds, Count, Calculate
Step 1: Dampen the towel Wet it until damp but not dripping.
Step 2: Place 10 seeds, evenly spaced Fold the towel over them or cover with a second damp towel.
Step 3: Seal in a bag or covered container This retains moisture.
Step 4: Keep warm and check daily Keep the towel moist. Remove any seed that grows mould.
Step 5: Count after the expected time For most vegetables the parent article gives 3 to 14 days. Count only seeds that have clearly sprouted.
Step 6: Interpret
- 8 to 10 sprouted: excellent. Plant at normal spacing.
- 5 to 7: moderate.
- 3 to 4: poor.
- 0 to 2: not worth planting unless it is all you have.
Worked Example
The parent article gives sowing multipliers by band (1.5 times for 5 to 7, 2 to 3 times for 3 to 4). Working it out directly: the multiplier is 10 divided by the number that sprouted.
- 8 of 10 sprouted: 10 ÷ 8 = 1.25, so sow about 1.25 seeds per plant wanted.
- 6 of 10: 10 ÷ 6 ≈ 1.7.
- 5 of 10: 10 ÷ 5 = 2.
- 4 of 10: 10 ÷ 4 = 2.5.
- 3 of 10: 10 ÷ 3 ≈ 3.3.
At 5 of 10 the arithmetic gives 2, which is above the parent article’s 1.5 times, so use the calculation when the result sits at the low end of a band. Ten seeds is a small sample, so treat every result as rough.
Common Mistakes
- Letting the towel dry out — seeds stop germinating.
- Drowning the seeds — a dripping towel rots them.
- Counting too early — different species take different times.
- Testing treated seed with bare hands — see the warning below.
Treated seed and mould
Seed that is dyed or labelled “treated” carries a pesticide coating, so handle it with gloves and wash your hands afterwards. Do not eat the tested seeds or let animals eat them. Moulds growing on the towel can irritate lungs, so do not breathe them in and discard the towel and moulded seeds outdoors.
What’s Next
- Learn next: Building a Seed Library — record results beside each seed lot
- Combine with: Seed Longevity by Species — which seeds to test first