Last Updated on September 18, 2026

Seed Viability Chart: How Long Vegetable Seeds Last

Most vegetable seeds stay viable for 1 to 5 years when stored properly, though a few last longer and a few last only a season. Onions and parsley are done in about a year, beans, carrots, broccoli and peas hold for about 3, and cucumbers, radishes and lettuce can still grow after 5 to 6. Age is only half the story: how you store the packet between now and next spring changes those numbers as much as the calendar does.

University of Illinois Extension gives a simple rule of thumb for storage: keep seeds cool, dry and dark, and add the storage temperature in Fahrenheit to the percent relative humidity. If that sum stays under 100, the seed is stored well; at 60°F that means the relative humidity has to stay under 40 percent. Illinois Extension recommends a spot ideally below 45°F, such as a sealed jar or bag in the refrigerator.

How long vegetable seeds last, by crop

The years below assume the seed was stored cool and dry, roughly following the rule of thumb above. They come from University of Illinois Extension’s seed viability guide unless a note says otherwise. Treat them as a starting point, not a deadline: a germination test, covered next, tells you for certain.

Numbers are from University of Illinois Extension’s seed viability guide, with the herb figures for basil, oregano and sage from its Good Growing blog. Squash, butternut squash and zucchini share the guide’s single “squash” listing, and cantaloupe uses its “muskmelon” figure. Garlic, potatoes and strawberries usually grow from cloves, tubers or runners rather than seed, so they are left off.

Test old seeds before you trust them

A germination test tells you what a chart cannot: whether this packet, stored the way you actually stored it, will still grow. University of Illinois Extension’s steps:

1. Count out 10 seeds of the same crop and variety.
2. Lay them on a damp paper towel, not soaking wet, and fold the towel over them so they stay separated.
3. Put the folded towel in a sealable plastic bag or container so it cannot dry out.
4. Label the bag with the crop name and the date.
5. Set it somewhere warm. Sunlight is not needed.
6. Check after the number of days to germination listed on the seed packet, or in 7 to 10 days if you no longer have the packet, according to Illinois Extension’s Good Growing blog.
7. Count how many seeds have sprouted a root or shoot. That count out of 10 is your germination percentage.

What to do with the result, per Illinois Extension: if all 10 sprout, plant as normal. If 7 to 9 sprout, do not throw the packet out, just sow it thicker than normal to make up for the ones that will not come up. If 6 or fewer sprout, buy fresh seed instead, since a rate that low will leave gaps even sown heavy. The germination temperature chart covers the other half of the equation, the soil temperature seeds need once you do sow them.

Store seed so it lasts

Storage is the variable you control. University of Illinois Extension and South Dakota State University Extension agree on the basics:

• Keep it dry first. If you saved the seed yourself, SDSU Extension says to make sure it is thoroughly dry before it goes into a container; damp seed is the fastest way to lose a whole packet to mold or rot.
• Use a sealed container. A jar or sealed bag keeps humidity out better than the original paper envelope alone. SDSU Extension warns that if you see condensation forming inside the jar, the seed was not dry enough or the container is being opened at the wrong time.
• Keep it cool and dark. Illinois Extension recommends below 45°F; SDSU Extension says to avoid sheds or garages where summer heat can climb past 90°F, and to keep relative humidity under 60 percent even outside a sealed container.
• The fridge or freezer helps, but only once the seed is dry. Colorado State University Extension explains that good storage needs low moisture (under about 8 percent) and low temperature together; a refrigerator or freezer supplies the cold, but only a moisture-proof jar keeps humidity from undoing it. Bring a cold container back to room temperature before opening it, so moisture from the air does not condense onto the seed.
• Label every packet with the crop and the year. Keeping saved seed in labeled envelopes, as Iowa State University Extension recommends, makes it easy to see which packets are old enough to test.

Tim’s own seed organizer setup covers containers and dividers for keeping a whole collection sorted this way, and his guide to choosing the right seeds is the place to start before you even open a packet.

Let the planner place them

Plan My Garden is free to start: enter your zip code, draw your beds, pick the crops you are testing or resowing this year, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates. Once you know which packets passed their germination test, the Seed Starting Calendar turns your last frost date into start-indoors, transplant and direct-sow weeks, and the Days to Maturity Chart helps you decide if an older, slower packet still has time to finish before fall.

Quick questions

How long do vegetable seeds last?

Most vegetable seeds stay viable for 1 to 5 years when stored properly. Onions and parsley last only about 1 year, corn, peppers, leeks and okra about 2 years, beans, carrots, broccoli, celery, kohlrabi, peas and spinach about 3 years, and beets, cabbage, cauliflower, eggplant, kale, pumpkin, tomatoes, turnips and watermelon about 4 years, while cucumbers, radishes and collards can last 5 years and lettuce up to 6, according to University of Illinois Extension.

What is the seed storage rule of thumb?

Keep seeds cool and dry, ideally below 45°F. University of Illinois Extension gives the rule of thumb that the sum of the storage temperature in Fahrenheit and the percent relative humidity should stay under 100, so seed stored at 60°F needs the relative humidity under 40 percent.

How do you test if old seeds will still grow?

Place 10 seeds on a damp paper towel, fold it over the seeds, seal it in a plastic bag or container, and keep it somewhere warm. Check after the number of days listed on the seed packet, or in 7 to 10 days if you do not know it, and count how many sprouted. That count out of 10 is your germination percentage, according to University of Illinois Extension.

What should I do if my germination test result is low?

If 7 to 9 of 10 seeds sprout, sow the seed a little thicker than normal rather than throwing the packet out. If 6 or fewer sprout, University of Illinois Extension recommends buying fresh seed instead, since that low a rate will leave gaps even sown heavy.

Does storing seeds in the fridge or freezer help?

Yes, but only once the seed is dry. Colorado State University Extension says good seed storage depends on keeping seed both dry, under about 8 percent moisture, and cold; pack dried seed in a moisture-proof jar before it goes into a refrigerator or deep freezer, and let the jar warm to room temperature before opening it so moisture does not condense onto the seed.

Related: Seed Germination Temperature Chart · Seed Starting Calendar · Vegetable Days to Maturity Chart · The Best Seed Organizer · Choosing the Right Seeds for Your Garden