How to Test If Old Seeds Are Still Alive (Paper Towel Method)
The paper towel test tells you in 7 days whether old seeds will germinate. 10 seeds, 1 damp paper towel, 1 ziplock bag.
The Method (5 Minutes Setup)
- Count 10 seeds from the packet.
- Dampen a paper towel.
- Place seeds on the towel. Space 1 inch apart.
- Fold the towel over the seeds.
- Put in a ziplock bag. Slightly open.
- Place in a warm spot (70-75°F).
- Check daily. Keep towel damp.
Reading Results (Day 7)
| Sprouted | Viability | Action |
|---|---|---|
| 9-10 of 10 | 90-100% | Plant normally |
| 7-8 of 10 | 70-80% | Plant thicker |
| 5-6 of 10 | 50-60% | Plant 2x density |
| 3-4 of 10 | 30-40% | Not worth planting |
| 0-2 of 10 | Dead | Discard |
Seed Shelf Life (Stored Cool + Dry)
| Variety | Years Viable |
|---|---|
| Beans, peas | 3-4 |
| Tomatoes, peppers | 4-6 |
| Lettuce, kale | 3-5 |
| Carrots, onions | 1-2 |
| Parsley, parsnip | 1-2 |
Common Questions
Can I test seeds without a paper towel? Yes, you can plant directly. But you waste 2-3 weeks if they’re dead.
How long does the test take? 5-10 days depending on variety.
Should I test every packet? Only if seeds are over 2 years old.
What temperature is best? 70-75°F for most.
Can I plant the sprouted test seeds? Yes. Carefully transplant.
Does the test damage the seeds? No.