Are Old Seeds Still Good? How Long Seeds Last and How to Test Them
A past-date packet doesn't mean the seed is dead. Check how long each crop lasts, run a 10-seed paper towel test and decide what to replace.
Often, yes. Most vegetable seed stays usable for about 2 to 5 years when kept cool and dry, while onion, parsley and parsnip are best bought fresh each year. If you’re not sure, run a paper towel test with 10 seeds: if 7 or more sprout, plant them, and if 6 or fewer sprout, buy new.
How long common seeds last
Published charts don’t match exactly, so the table below reflects lists from Illinois Extension, Nebraska Extension and Purdue. Where they disagree, you’ll see a range. Flower figures come from Purdue’s list. All of these assume good storage, so seed kept in a hot shed may fade much sooner.
| Approximate life | Vegetables and herbs | Annual flowers |
|---|---|---|
| 1 year | Onion, parsley, parsnip | Aster, pansy, annual phlox, salvia, verbena, vinca |
| 2 years | Okra, pepper, sweet corn | Impatiens, marigold, petunia |
| 3 years | Beans, broccoli, carrot, peas, spinach | Cosmos, lobelia |
| 3 to 4 years | Squash, tomato | |
| 4 years | Beet, cabbage, cauliflower, eggplant, kale, pumpkin, Swiss chard, turnip, watermelon | Alyssum, poppy |
| 5 to 6 years | Cucumber, lettuce, muskmelon, radish | Calendula, nasturtium, zinnia |
Leek is the odd one out: one list gives it 2 years and another gives it 6, so test it before relying on it.
Why old seed fails
Seeds are alive, and they slowly use up their stored reserves. Heat and moisture speed that up. Purdue notes that storage conditions can matter as much as the type of seed, or more.
A seed can also sprout without being strong. Illinois Extension points out that vigor drops before germination does. If only a few seeds in a packet sprout, the survivors are less likely to grow into strong plants.
How to run a paper towel germination test
- Count out 10 seeds. If you have plenty, use 25 or 50 for a more reliable result.
- Lay them on a damp paper towel and fold it over.
- Put the towel in a plastic bag or lidded container so it doesn’t dry out. Label it with the crop, the date and the days to germination from the packet.
- Keep it warm, at about 70 to 75°F. It doesn’t need sunlight.
- Check every couple of days and re-dampen the towel if it’s drying.
- Count the sprouted seeds after the expected days to germination. Slow crops can take longer, so give them up to 2 or 3 weeks before the final count.
| Seeds sprouted (of 10) | What to do |
|---|---|
| 10 | Plant normally. |
| 7 to 9 | Plant, but sow more seeds than usual. |
| 6 or fewer | Buy new seed if you can. |
Some perspective helps with slow or naturally low germinators. Nebraska Extension’s table of federal minimum germination standards lists 55% for carrot and pepper, 75% for tomato and 80% for lettuce and cucumber. New seed isn’t expected to hit 100%, so a borderline carrot result may still be usable if you have plenty of seed. Weak sprouts are a different matter, because they die off at a higher rate once planted.
When to buy fresh
- Short-lived seed. Onion, parsley and parsnip rarely justify the risk after a year.
- Crops with no second chance. If a failure would cost you the season, such as peppers in a short-summer area, a new packet is cheap insurance.
- Poor test results. Six or fewer of 10 means replacing the packet, unless the variety is rare or saved, in which case sow it thickly anyway.
- Damp or moldy packets. Seed that started sprouting in storage won’t grow when planted later.
If seed passes your test but still fails in the bed, the problem may be depth, moisture or soil temperature instead. Our guide to seeds that won’t germinate walks through each cause.
How to store seed you keep
- Keep seed cool, dark and dry. Illinois Extension recommends below 45°F, in a sealed jar or bag in the refrigerator if you have room.
- Use the fridge, not the freezer, for small quantities, as Purdue advises.
- To absorb moisture, put a layer of uncooked rice or powdered milk in the bottom of the jar and separate it from the seed with a paper towel.
- Let chilled jars reach room temperature before opening them.
- Keep the original packet, or label each container with the plant name and year.
- Keep treated seed, which is often brightly coated, away from children and pets, and never eat it.
Bottom line
Don’t throw out old seed on age alone, and don’t trust it blindly either. Check the chart, test anything doubtful in January or February, and buy fresh for short-lived crops. That leaves you time to reorder before your sowing dates arrive, and it fits neatly into your winter garden planning.
FAQ
Do seeds expire on the date on the packet?
No. The date tells you the season the seed was packed for, not the day it stops working. Many seeds keep going for years after it, though germination gradually falls.
Can I plant seeds that are 10 years old?
You can try, but expect a low result. Most charts stop at around 5 or 6 years, so run a test first and sow thickly if anything sprouts.
Should I store seeds in the freezer?
Purdue advises the refrigerator instead of the freezer for home storage. An airtight jar in the fridge is simple and works well for small amounts.
Will soaking bring old seeds back?
No. Soaking can help some large seeds take up water faster, but it won’t revive seed that has lost viability.
