Q&A: Do Seeds Have Expiration Dates?
Q: Will seeds I bought for last year be okay to use this year? Do seeds have an expiration date?
A: It depends on the type of seeds and how they were stored. If your seeds were kept in a cool, dry place, there's a good chance they're still viable, but expect a lower germination rate — exactly how low depends on the species. Seed corn is best used the current year (after that germination is greatly reduced), but tomato seeds can last for more than four years if stored well. Seeds for some perennials seem to last forever while some such as delphinium must be sown shortly after harvest. Annuals such as cosmos, marigolds, petunia and stock can last for several years. Parsley has to be sown right away.
The germination rate continues to decrease over time until eventually you're better off buying new seed so you're not wasting garden space, energy and time. To test your seeds, space several out on a few layers of moist paper towels, roll up so that the seeds don't touch, and enclose the bundle in plastic wrap so it doesn't dry out. Place in a warm bright location (65 to 70 degrees is fine) but away from direct sun. Check the seeds every couple of days. If they haven't germinated — or only a few have sprouted — in a couple of weeks, chances are they're no good. If you prefer just throwing caution to the winds and not testing the seeds, be sure to sow more heavily to make up for lower germination rates.
Vegetable seed viability
beans - 3 years
beets - 2 years
carrots - 3 years
corn - 2 years
cucumbers - 5 years
lettuce - 3 years
peas - 3 years
peppers - 2 years
pumpkins - 4 years
radishes - 5 years
spinach - 5 years
tomato - 4 years
watermelon - 4 years
Q: Some of the packs of seeds I've ordered (tomato, okra, peppers, etc.) contain 30 or more seeds. I don't need to plant this many. How can I best save some seeds for next year? Also, can I simply save some seeds directly from the inside of the pepper, for instance?
A: Generally, it's best to store seeds in airtight containers (baby food jars and film canisters are great) in a cool, dry place where the temperature doesn't fluctuate very much — the refrigerator or a shelf in the basement are options. Be sure to label and date the jars to prevent future mysteries! If these are seeds you've collected, make sure they are completely dry or they may mold in storage.
It's not usually worthwhile to save seeds from hybrid varieties, since the next generation usually won't produce the same quality of plants and fruit. If you want to save seeds from your vegetable garden, allow the fruit to fully ripen, almost to the rotten stage, then scrape out the seeds and let them dry in an airy place. Once the seeds are completely dry, put them in airtight containers and store them in a cool, dry location.