How Long Do Seeds Last? (+ Cheat Sheet on Seed Expiration Dates)

Have you ever dug into a pile of old seeds and wondered if they’re still good? How long do seeds last anyway? The short answer: It depends. Here’s what you need to know about storing your seeds properly and what you can do to maximize the shelf life of your vegetable, herb, and flower seeds.

Linda Ly
How long do seeds last? (Plus a cheat sheet on seed life)

The beginning of spring usually sees me sprawled in the middle of the living room floor, with all my ammo boxes, laying out rows and rows of seed packets sorted by vegetable, and then by variety.

Some are even color-coded… and I suddenly realize I have a rather strange obsession with collecting 12 different types of purple tomatoes (and counting).

Related: Grow Tomatoes Like a Boss With These 10 Easy Tips

Inevitably, a handful of seed packets get tossed in the compost pile as I double-check the dates… peppers from 2016, onions from three years ago. Yikes.

Some seeds I’ve only sown once or twice but still have half a packet left, some I’ve saved… and saved… and saved… because they’re so easy to save by the bagful every year (I’m looking at you, beans).

Others are rotated every few seasons as I try new varieties, and by the time I make it back to those Parisienne carrots, it’s already been a couple years.

Are they still good? Should I get new ones? How long do seeds really last, anyway?

I’ve combed through countless seed sites and extension sites over the years, wondering this very question.

How long do seeds last?

There seems to be no consensus, especially when you take into account the environment the seeds were stored in, the quality of the original crop the seeds were harvested from, and even the condition of the seeds themselves, as treated seeds will have a different lifespan than seeds in their natural state.

Seeds have a shelf life (as all living things do), and depending on where your particular shelf is, the viability of your seeds can vary by as much as a year or two.

When someone asks, “How long do broccoli seeds last?” a safe answer is three years, but in ideal conditions your seeds could still actually sprout after five.

So, you see where our dilemma lies.

Determining the germination rate of garden seeds

What are ideal storage conditions for seeds?

In a perfect world, we’d all have second refrigerators with perfectly controlled humidity levels in which to store our seeds.

Our seeds would live in this cool, dark, dry environment and 10 years later, those very first tomato seeds we’d ever bought would still be viable.

In reality, our homes go from hot to cold at the turn of the seasons, we sometimes forget our seed packets outside overnight (or at least I do), and an old shoebox will have to do for storage.

We can’t really fault ourselves either. Who knows what the seed went through before it even reached the store?

A glass jar on a counter filled with nasturtium seeds

What temperature should you store seeds at?

With all the uncertainty about how and where seeds should be stored, here’s a proven fact:

Seeds store best below 40°F with less than 10 percent humidity, tucked inside airtight containers in a dark environment.

Every time a seed experiences less than ideal conditions, it suffers a decline in quality. It may not die right away, but it might take a little longer to germinate.

Read more: 6 Foolproof Tips to Germinate Hard-to-Start Seeds—Fast!

Eventually, it will fail to germinate at all.

Using the baggie method with coffee filters (or paper towels) is a good way to test seed germination.

By taking a sample of 10 to 20 seeds and pre-sprouting them in baggies, you can gauge how viable those seeds are before committing to starting more of those seeds or transplanting the seedlings.

A good rule of thumb to know: less than 50 percent germination rate means it’s time to buy new seeds.

Bean seed germinating

Why seed vigor matters

According to Oregon State University, vigor is the “ability of those seeds to produce normal seedlings under less than optimum or adverse growing conditions similar to those which may occur in the field.”

That is, the ability of your plants to survive in the ground outside with all the elements working against them (even if they’ve been hardened off), as opposed to being coddled inside in a cozy baggie.

Bean seedling with great vigor
Above: A bean seedling that sprouted within days of being sowed. The cotyledons clearly look healthy and vibrant.

While a germination test can predict viability, it can’t truly predict vigor: how well a seedling will grow in terms of health, strength, uniformity, and root system, not to mention its production of flowers and fruits.

A seedling with compromised vigor may have a missing cotyledon, look stunted or scrawny, or seem overall slower to develop than seedlings from fresher seeds.

A bean seedling missing cotyledons
Above: A bean seedling (sprouted from a three-year-old seed) with missing cotyledons. This seedling will never develop into a normal productive plant.

Try as they might, sometimes older seeds just don’t have it in them to sprout, grow, and go all the way to seed again. A will to germinate does not equal an ability to thrive.

What the pros say about the average lifespan of seeds

The cheat sheet below takes the average life expectancy of seeds from a variety of sources, including the cooperative extensions of Oregon State University, Colorado State University, Purdue University, and Virginia State University.

Consider it more as a guideline, as the shelf life of your seeds ultimately depends on the date on the packet and how carefully you’ve stored them since then.

Garden Betty’s Seed Life Cheat Sheet

Download printable PDF version
VegetablesShelf Life
Asparagus3 years
Beans3 years
Beets3 years
Broccoli3 years
Brussels sprouts4 years
Cabbage4 years
Carrots3 years
Cauliflower4 years
Celery3 years
Chard3 years
Chicory4 years
Collards4 years
Corn (sweet)2 years
Cress5 years
Cucumbers5 years
Eggplant4 years
Endive5 years
Kale4 years
Kohlrabi3 years
Leeks2 years
Lettuce3 years
Muskmelons5 years
Okra2 years
Onions1 year
Oriental greens3 years
Parsnips1 year
Peas3 years
Peppers2 years
Radishes5 years
Rutabagas4 years
Salsify1 year
Spinach3 years
Squash (summer and winter)4 years
Tomatoes5 years
Turnips4 years
Watermelons4 years
Herbs and FlowersShelf Life
Basil5 years
Chives2 years
Cilantro2 years
Fennel3 years
Oregano4 years
Parsley2 years
Sage4 years
Annual flowers1 to 3 years
Perennial flowers2 to 4 years
A dried flower head and calendula seeds scattered on a counter

Common questions about storing seeds

Can you freeze seeds to make them last longer?

Yes. All seed banks freeze seeds that are intended for long-term storage, and you can do the same at home.

The key is to start with thoroughly dried seeds (if you saved them from your own plants) and store them in airtight, freeze-proof containers to reduce the risk of seeds absorbing moisture. Keep the seeds in a reliable freezer that maintains consistent temperatures and isn’t opened often.

When it’s time to plant, thaw the frozen seeds overnight at room temperature before planting them.

What temperature will kill seeds?

Seeds begin to die at temperatures above 108°F and are completely sterilized at 140°F (which usually happens in hot compost piles). However, it only takes consistent high temperatures over 90°F to affect the embryo inside a seed and lessen the chances of germination.

Avoid storing your seeds in an attic or uninsulated garage, or inside a hot car on a sunny day. If ideal storage conditions below 40°F with less than 10 percent humidity aren’t possible, keep your seeds in the coolest (and driest) part of the house, like a closet in a north-facing room or a dehumidified basement.

Should you vacuum seal seeds?

If you want to store seeds long-term, vacuum sealing is the ultimate method of seed preservation. Start with very dry seeds (they should shatter or snap in half cleanly, rather than smash or bend under pressure) before vacuum sealing them in a plastic bag and storing them in a fridge or freezer (below 40°F).

Do seeds need air in storage?

No. In fact, seeds store best in airtight containers in consistently cool, dark, and dry conditions, such as those found in a fridge or freezer.

As long as the seeds were sufficiently dry before storage (they shatter or snap in half cleanly, rather than smash or bend under pressure), the lack of air—along with low humidity—helps them stay dormant and viable longer.

Do seeds expire?

Seeds don’t necessarily “expire” or go bad (unless they’re left in conditions that cause them to mold or rot). However, they do deteriorate in quality and vigor over time. Think of the dates printed on seed packets like those “Best by” dates on food; they aren’t set in stone, but are more of a guideline as to how long the seeds are at their peak viability.

If you try to plant seeds past those dates, you may still get a few of them to germinate, but the overall yield will be lower.

This post updated from an article that originally appeared on March 17, 2015.

View the Web Story on how long seeds last.

52 Comments

  1. Hi Linda,
    This is a great resource and thank you for providing it. One note — you have a link to a Virginia Tech publication but identify it as “Virginia State University”. That’s not a correct name. Virginia Tech or Virginia Polytechnic Institute and State University would be accurate. They have a really great ag school and should get appropriate credit. Thanks and have a great day!

  2. Last spring I discovered a box with some old “emergency seeds” that I’d purchased back in 2009 but never used. (The seeds had been stored down in the basement all this time, inside the heavy metal box that they had shipped in.) I planted 16 heirloom tomato seeds and 16 heirloom sweet bell pepper seeds. They all sprouted and grew healthy, once I I figured out I needed to use a plant light, that is. I used your advice on gardenbetty.com on how to grow seedlings indoors and on transplanting, hardening, and what to put in the hole when planting–and it helped a lot! I ended up with a huge crop of beautiful heirloom tomatoes and some green peppers.(I will say that the peppers did not grow very big, but it might have been the weather here last summer and not the fault of the seeds–especially since the pepper plants themselves looked fine, both indoors and once planted in the garden.) The tomatoes, on the other hand, did great all season long.. I canned some and gave hundreds away to friends, to the Salvation Army, etc. I even pulled up a few tomato plants and set them on newspapers in my toolshed near a window to be able to harvest a few dozen more tomatoes. This experience proved to me that a good heirloom seed can sometimes grow just fine, many years later, when stored optimally.

  3. There is a seed vault in ???? where they are trying to preserve seeds in case of a global catastrophe. Couldn’t we try to achieve their storage conditions and if so what are they?

    1. There are many seed vaults all over the world, but you’re probably thinking of Svalbard in the Arctic Circle. And yes, you can, but most people don’t have walk-in freezers that are dialed in to the perfect humidity levels needed to sustain long-term seed storage (in special foil packs, no less).

      For the average home the best storage condition is this (copied from my post):

      Seeds store best below 40°F with less than 10 percent humidity, tucked inside airtight containers in a dark environment.

  4. Betty, wow, really good job! Amazing idea for the post as I didn’t know many of these information. I don’t keep my seeds long, for sure, because I have got a lot of space to grow plants; however, you’ll never know what can happen. Do you think that this chart matches to all varieties of one kind? For example, I have Salsify on which date is a bit more longer than one year (I have ordered it on https://gardenseedsmarket.com/scorzonera-black-salsify-seeds-scorzonera-hispanica.html ), I hope that seeds will be still “to use” 🙂

    1. These are just rough guidelines of how long the seeds should last, but in general, they apply to all varieties of the same plant. Your salsify will likely still germinate after a year, but it may get progressively weaker each year after in terms of how long it takes to germinate and mature. You never know unless you try. 🙂

  5. Thanks for such good information on a perennial question. A couple years ago, more as a lark than an act of optimism, I planted some 20-year-old Tithonia seeds (Mexican Sunflowers). To my amazement, they sprouted and grew into vigorous plants! I was extremely gratified, although I realize this is probably highly unusual.)

      1. Yes, it was fun to see them come up! A few years later, though, I was bummed when I planted a fresh batch and not one came up. Couldn’t understand what happened until I discovered belatedly that they don’t germinate unless planted shallow enough to be exposed to light. Details, details. =8^)

  6. Thank you so much for the work you put into this article. I appreciate it’s thoroughness and creativity.

  7. I have a habit of purchasing seeds and then never using much of them. I still have some pea seeds from 1980. I know that under certain circumstances seeds can last a very very long time. I will have to plant some of these old seeds this year and see if any of them take.

  8. Thank you for the awesome article! Until now I had to be really careful when buying seeds, because it was hard to tell whether they were going to last long or not, and if they could sprout and grow with enough vigor at all. But with this cheat sheet I can finally sort out my crop rotation plan with ease!

  9. I just went through the list & sorted out old seeds, throwing away any that were beyond this list. After reading comments, I retrieved them from the garbage. Will have to wait until next year to test.

    Excellent article & informative comments!

    1. Thank you! I would definitely test the germination rate of any seeds that are close to the suggested expiry dates in this post, but if you have the time and inclination, you could always test the ones that are far beyond expiration just for fun. 🙂

  10. I found a pack of basil seeds that were dated for the 2003 growing season. I sprinkled them on soil in April and I’ve got a bunch of basil plants that are about three inches high now and growing taller each day. The seeds were in an office cabinet for the past 15 years so they weren’t stored in any special way.

  11. I have been gardening on a budget for over 30 years. When I bought my first house, the old fellow who sold it to me left some tomato seeds. If I remember correctly they were early girl and judging by the packet they were several years old. I used these seeds for 16 years until I sold the house and left the seeds for the new owner.
    One of the last crops that I grew in that house included paprika peppers. I dried them and used them in the kitchen until they were almost all used up. 14 years later, I found one dried pepper in my kitchen cupboard and decided to try the seeds for viability. I planted 12 seeds and all came up on the 3rd day. I gave most of the plants away but grew 4 of the remainders. One plant alone has provided 35 peppers 8-10inches long.
    In both cases I did nothing special to preserve these seeds. They were simply kept in a dry place.

  12. First I would like to thank you for all the time and work that you put in this study. I want to use this to judge how long to keep my seeds. But, are these seed expectancies base on shoe box storage or refrigerated storage?

      1. Again thank you. 🙂 I will print this time table out and put it in the shoe box with the seeds.

  13. I love the water and paper towel germination test. That let’s me know if I am good to go or not. I have an obsession with seeds and yes some get really old….

    1. I am too obsessed with seeds… when I go to farmers market I save the seeds on what ever I picked up… but when I grow them and which they come out healthy and full of life and by the time they flower they never bear fruit.. I would assumed farmers market that claim themselves organically grown will have no chemical to prevent from re producing thru their seeds… I am lost… I want to see what I plant and know were its coming from…. do you think this local farmers market are in just for the fad of locals wanted to support locals…

      1. Only heirloom and open-pollinated varieties produce stable seeds that stay true to the breed. (Read more about this in my seed-saving post: http://gardenbetty.com/2011/09/a-guide-to-saving-and-storing-seeds/ )

        If you saved the seeds from hybrid vegetables and tried to grow new plants with them, they may produce sterile seed, or produce fruits that don’t resemble the parent plant at all. There ARE organically grown hybrids, but they’re not ideal for seed saving.

      2. The reason why that happens is most fruit is harvested when they first become ripe. But in order to save seeds from them they need to stay on the vine a lot longer.

  14. Thank you for the handy list! Like many, I just had no idea what to expect from my old seeds. I definitely had some failures this year: 3yo onions and 4yo spinach. I’m still waiting to see what happens with some 3yo peppers. I think it’s time to edit my stash!

    1. This year I combined all my leftover carrot seeds from a few years ago and just broadcast them into a tray… whatever decides to spring up will be a bonus this season!

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