How to Know If Those Seeds Are Still Good
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How long do garden seeds last? How do you tell if your old seeds are still good? Let’s find out!
Wintertime is the season when these questions matter. The gorgeous seed catalogs arrive in the mail, tempting you with beautiful photographs.
But before you go crazy, it’s time to inventory your leftover seeds to avoid duplication and determine viability.
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How Long Do Vegetable Seeds Last?
Seeds are living things and their viability is affected greatly by the way they are stored. Most experts agree on dark, cool, and dry conditions as being the best. We keep some of our seeds in the refrigerator, but most are in open boxes in the dining room—probably not the best location!
Some seeds inherently have a longer life expectancy than others, too. Most last for a couple of years if stored in a dry, cool place. Consult the table below to see how long some of the most common garden seeds last.
| Replace after… | Type of Seed | |
|---|---|---|
| 1 Year | Lettuce, onions, parsley, parsnips, salsify | |
| 2 Years | Corn, leeks, okra, peppers | |
| 3 Years | Asparagus, beans, broccoli, carrots, celery, kohlrabi, peas, spinach | |
| 4 Years | Beets, brussels sprouts, cabbages, cauliflower, Swiss chard, eggplants, kale, pumpkins, radishes, rutabagas, squashes, tomatoes, turnips, watermelons | |
| 5 Years | Cucumbers, endive, cantaloupes | |
| Seed viability data gathered via Colorado State University Extension. | ||
How to Tell If Your Seeds Are Still Good
If I have a question about the viability of some seeds—such as those beans that someone gave me back in 2012—I will test a few.
This is as easy as placing ten seeds on a damp paper towel, folding it up, and placing it in a plastic bag. Put the bag in a warm spot and check after a week or so to see if any of the seeds have sprouted.
- If 2 out of 10 germinate, that means a germination rate of about 20%—not too good, so I would either plant more of them than usual or buy fresh seeds altogether.
- If 8 out of 10 germinate, that means 80%—not bad at all, and I can likely get away with using them for another season.
Once you have determined what you need, you can shop with a clear plan in mind and be less likely to overbuy.
Have fun looking through this year’s seed catalogs and dreaming of your best garden ever. Summer is just a page away in a seed catalog!
Speaking of which, check out our list of free garden catalogs and sites.
Robin Sweetser
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I package my seeds in small glass or plastic containers and store them in he freezer. Most of my seeds are viable 10 years longer than the chart above mentions.
What about flower seeds like Zinnias, Sweet William or Foxglove?
The Svalbard Global Seed Vault keeps seeds viable for decades, ( maize, rice, wheat, cowpea and sorghum to European and South American varieties of eggplant, lettuce, barley, potato etc.). They are sealed in specially-designed four-ply foil packages that will be placed in sealed boxes.
Around the planet, there are nearly 1700 seed banks besides Svalbard.
As I have been able to determine, proper preparation of the seeds and their packaging, can ensure that most seeds will outlast most of their owners.
Though I am not a survivalist, I am prudent enough to keep at least 300 different seed varieties in deep freeze.... even my pine cone seeds.
You know, just in case disaster strikes.
Do I close the plastic bags completely or leave the bag open for air? Also, do I spritz with water while waiting to keep things moist?
If seeds are freeze dried (as in a Harvest Right machine) then packed in a mylar bag with an oxygen absorber, will the seeds remain viable?
I want to test some old seeds. If they germinate can I expect the adult plants to grow as well as plants from fresh seeds would have? Seeds are cheap enough but this seems like a good way to spend some down time.
Thanks.
I just put old seeds in a small separate section of my garden together. If they germinate & look healthy I transplant them. If they come up & look spindly I let them grow for a bit & then turn them in to break down into the soil.
I can't say it will or not for you, but personally, I find that the older the seed is, the less that germinate and the more spindly and weak the growth is. Some seeds kept in the freezer never germinated at all. I've decided to dispose of seeds after three years as it is a lot of work to prepare and plant and then have a poor result and have to replant several weeks later with other seeds.
Are you aware that a 2,000 year old date seed was planted in the desert of Israel and it grew to full size? I seem not to be able to grow anything, but I keep trying. Thanks for the info how to test seeds.
I found some Phlox seeds in their original seed packets in my basement that were over 10-20 years old. Instead of throwing them away, I threw them into my side yard and I now have a beautiful side yard every season that is full of white and pink (in different hues) phlox. When in bloom their stalks are 3-6' tall. So glad I didn't toss them out !
