How to Test Vegetable & Annual Seeds

REMEMBER the old adage Waste not, want not? You can apply this bit of wisdom to your “old” annual and vegetable seeds, too. For instance, consider the Cherokee Purple tomato seeds pictured above. I purchased these back in 2010, and have plenty left over. But are they still viable after two years have passed? Well, let’s find out.

To test for seed-viability, grab a paper towel, a plastic bag and ten seeds. Why ten seeds? Because this number will permit you to calculate the germination expectancy in terms of percentages. Consequently, if only 5 out of 10 seeds sprout, you’ll know to plant twice as many seeds in order to achieve 100-percent of the crop you want.Β  Here’s the testing procedure:

Spritz the paper towel with water just to dampen it. Then arrange 10 seeds on the lower portion of the towel.Β  Fold the towel so that both sides of seeds receive moisture.

Next, place the towel in a plastic bag, and seal it to lock in moisture. Then label the bag as to seed-type, the year the seeds were packed for sale and date of your test, as above. Set the seeds some place dark and warm. Mine go in my desk drawer.

Check the seeds daily, by opening the bag, removing the towel, and unfolding it. Some seeds germinate very quickly, while others can be poky. Re-moisten the towel if seems dry.

The results:

After only 4 days, all 10 of my Cherokee Purple tomato seeds sprouted. Yeah! TheseΒ  seeds are 100% viable.

However, I can expect only 70% germination for my two-year-old spinach seeds. For three (out of ten) did not germinate.

My old snapdragon seeds have shown no sign of growth after four days. This isn’t surprising. Snapdragons are slow to germinate even when fresh. I’ll give them up to 14 days to prove themselves.

Now, I hope I’ve given you news you can use. After all, why throw out your old seeds if they can potentially provide you with beauty or food?Β  Waste not, want not…indeed!

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Related Posts:
Making a Greenhouse & Sowing Seeds
My Favorite Seeds Suppliers…& Yours (2013 Edition)
Winter-Sowing 101


  1. That is exactly what I do, right down to the ziplock bag, paper towel and marker! Though sometimes I write on the paper towel and roll it up so I can fit 4 or 5 rolls in a recycled gallon bag.

  2. Mary – Yes – good idea to mark the paper towels (I suspect a permanent marker won’t run?) and use just one bag. And no need to use an entire paper towel, either. One small strip will suffice for 10 seeds.

  3. Best vegetables are healthy for us .

  4. Cary Bradley says:

    Of course you would picture my all time favorite! You rock! thanks for the reminder to test before replacing… penny saved, penny earned.. plus shipping ;)!

  5. Cary – You’re a fan of Cherokee Purple, too? I fell madly in love with this heirloom tomato back in 2010. But in the interest of variety I neglected to plant it in 2011 — and boy was it missed. So glad I kept the seeds — and that they are still viable — for 2012!

  6. Cary Bradley says:

    Yes, it has been my favorite for about 10 years, I think. I have distant Cherokee heritage, so the name won a place in the garden, but the taste won me over hands down! Last year’s seedling ID tags were mixed up in gardening accident πŸ™‚ so ate none at all. Very much looking forward to tasting them this year, very hopeful!

    Wonderful gardening friend sent a seed sampler of favorite New England heirloom tomato varieties which includes too many varieties for my space. Feel like Meryl Streep in Sophie’s Choice.. but excited to explore new favorites.

    Off now to do my KLJ-inspired winter sowing. Please do not tell the groundhog that I am so late starting :). Enjoy this great day, my friend!

  7. Carol May La Mountain says:

    Thank you for sharing your wonderful program on winter seed sowing with the Helderview Garden Club at Cornell Cooperative Extension in Voorheesville, NY. last night. I am so excited and motivated. I have only one jug presently, so the decision as to what goes in there is my major concern. Maybe I’ll do a raffle to solve that dilemma. Thank you for all your inspiration.

  8. Cary – New England heirloom tomato sampler — sounds like a great gift to receive! Hope you’ll report back on the varieties and how each fared in your garden. Always fun to try new things, right?

    Carol May La Mountain – Well, I had a great time speaking with your club! So glad to hear you feel inspired to winter-sow you garden — let me know what you decide to plant, okay?

  9. yehhh, and then i delicately plant in soft soil, the seeds which have sprouted so NONE are wasted…

  10. Valerie C. says:

    Another great piece of information! My mom was an avid gardener and great cook who passed away at a young age. I’m a novice at both, but, I’m learning so much here. Thanks!

  11. ArtistryFarm – Well, yes, especially if you do your testing in spring, when the sprouted seeds can be realistically planted outdoors! (I’ll confess that all but my spinach seeds were sacrificed for the sake of the article above.)

    Valerie C. – I’m glad you find this site useful. I suspect you well on your way to becoming a great gardener and a phenomenal cook!

  12. you’re reading my mind, how funny is the timing on this. just yesterday i ran across a whole bag of assorted seeds, and knowing how, well, lets just say, frugal i am, i have been wondering if they were any good. now the tale will be told. wish me luck, it would be lovely not to waste any of the seeds.

  13. Cindy Sue – Glad this is news you can use!

  14. Kevin, What seed companies do you recommend for good quality? I know your dislike for anything Monsanto. Where do you purchase your seed?

  15. Anne – Thanks for asking! Here are two posts you will find helpful: My Favorite Seed Suppliers…& Yours and Keep Monsanto OUT of Your Veggie Patch.

  16. Has the weird warm weather this winter affected your winter sowing? Are plants germinating too early? I was all ready to put the seeds in the soil yesterday–but I worried that it was actually too warm.

  17. Martha – Thanks for writing. Which zone/region are you in? (And please forgive me if I’ve forgotten).

    The weird weather has not affected my winter-sowing. Mercifully the seeds haven’t sprouted yet, probably because the pattern has been thus: a few warm days followed by a few cold ones. And most nights have dipped to near- or below-freezing.

    I always sow perennials and hardy annuals first. I wait until March to sow tender annuals and veggies.

    Whatever you plant during this freaky winter, it’s probably wise to hold back a few seeds. Just in case.

  18. Judy Shepherd says:

    Kevin: I LOVE finding your posts, like a note in the mailbox from a friend! I asked a question on an old post about herbs, but I’m sure you haven’t seen it. If I wanted a special place to plant herbs, what are the best conditions (soil and sun)?

  19. Hi Judy – Are you referring to indoor conditions for herbs? Most want full sun, a growing-medium that drains well, temperatures which do not exceed 65F, and moisture only when necessary. Commercial, all-purpose potting mixes are terrific for herbs. Clay pots are a must. Water only when the top inch of soil feels dry, and then water thoroughly, until excess seeps through the drainage hole. Then empty the saucer at once. Hope this was helpful to you — so sorry I missed your question when you originally posted it.

  20. This is exactly what I did last Thursday.. I’ve got loads of old seed.. most of it I pretty much know what is good or what is not but there are few that are iffy.

    One is some okra seed I saved from my garden last year that I got from my dad who lives 2000 miles away. I had loads of seed okra on the stalks to cure but then the deer decimated them.. I never counted on that one since they’ve never done that before.. I was able to harvest a few pods of different maturity levels and let them dry out in my basement.. Im hoping they were far enough along to be viable but Im not certain so Im testing.

    Two others are a purple/black cherry tomato & a yellow beefsteak type tomatoes I got from our organic CSA a couple years ago. Im hoping to have at least 50% viability.. That’d be ok by me. πŸ™‚

    So far, none have germinated.. its probably not warm enough for quick germ. where they’re at. I should put them on top of my computer body I think I will. πŸ˜‰

    I’ve found the purple/black tomatoes are my favorites.. Yum!! Our CSA grows them so that is where I had my first taste several years ago.
    Last year I grew both Black Krim & the Cherokee Purple.. They were far and above my favorite tomatoes in the garden. I grew 15 tomato varieties and they’re still my favorites.

  21. Good Morning .
    Yes i agree with Judy, its great to sit down at the laptop Sunday morning with my tea and open your email Kevin. Fills my head and my day with wonderful gardening plans for spring and summer πŸ™‚ and visions of warm sunshine … forecast is for -10c and more snow tonight … πŸ™

    I have a Q for U. What about the seed testing method where you float them in a glass of water and the ones that sink are viable and the floaters are dead ? Its a much faster method for sure, but is is vaild in your opinion ?

  22. Cherokee purples are the best in someone’s tomato pie….. Come on summer!!!!

  23. badger gardener says:

    I save and use all of my seed packets since I use so little per season. I keep them in a repurposed wooden CD box and usually get most to regerminate past the dates listed. I hope you won’t mind a story about what happened to that collection just this morning. My 5 and 8 y/o boys were busy playing out a battle between the Autobots and Decepticons in the world of Transformers Prime. My 8 y/o discovered my seed box was the perfect stand-in for the Nemesis, the Mothership of the Decepticons. I offered up some other options , but apparently this was shaped perfectly for the mothership. I told him I was not going to empty out the seeds for him, but he assured me the Decep’s only had to land on top. Well, of course, in the final battle the box was upended and out spilled a nice variety of seeds. The good news is my winter-sown seeds are already safely tucked away in their mini-greenhouses, my personally saved seeds are kept elsewhere, and my Baker’s Seed catalog finally arrived. Having to replace some seeds is a small price to pay to see the defeat of the Decepticons : )

  24. Marcia Mattingly says:

    I have germinated old seed many times but, I have often wondered if the resulting plant is as vigorous as a plant from newer seed would be. Do you know if anyone has done any research on this?

  25. Hi Lynn – From reports I’ve read, the seed-floating test is unreliable at best. Certain seeds will float on the surface even if they are still viable.

    badger gardener – I just shot coffee through my nose. What a great story!

    Marcia Mattingly – I know that my old, still-viable seeds have performed just as vigorously as the “newbies.” But I do not know of any scientific studies on the matter.

    And here’s an interesting tidbit from Wikipedia. The oldest carbon-14-dated seed that has grown into a viable plant was a Judean date palm seed about 2,000 years old, recovered from excavations at Herod the Great’s palace on Masada in Israel. It was germinated in 2005.

  26. I am sure this paragraph has touched all the internet viewers, its really really good paragraph
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  27. Kevin,
    Thanks so much!!! It will save me from alot of disappointments!

  28. Marjie T. says:

    Thank you! helpful and a good thing to do right now:)

  29. Hi Kevin,
    What a great and useful post – thank you!

    In one of your comments above your link to your post “Keep Monsanto OUT of Your Veggie Patch.” is broken (I think the date may be wrong). I searched for it and found it here:

    Glad I searched for it – and thank you so much for linking to it here on this post. I was totally unaware of this, and it’s such an important issue (heartbreakingly important for our whole planet). Will be sure to watch out for this from now on. Up to 80% market share! How horrible!

    Love your blog for its beautiful pictures and easy to follow tips. But can’t tell you much I appreciate tips like this one, and that link that you included.

    Great, great site. Always makes me smile. Better yet, rather than being off-putting you make everything you do seem ‘do-able’, even for the novice or intimidated (I’m both!) and make me want to try it myself! That’s a rare skill!

  30. Thanks for this tip. I was going to dispose of all my old seeds this month but now I’ll give this a try and maybe save a few dollars.

  31. OK I am about to do the big test on the random seeds I have in my freezer, maybe 10 or 15 years old???? The discovery of 2000 year old seeds are giving me hope.

  32. I’ve got a lot of older seeds (I do not know how old they are) that we need to go through and test. I harvested these seeds, they weren’t store-bought, so I’m curious if any of them are still viable!
    (Does the dog get a treat now? πŸ˜‰ LOL)

  33. SueEllen says:

    Thank you so much for this post Kevin!!
    I have a whole can full of older packaged seeds that I can try this out on.
    Yes, like you say, waste not, want not…indeed!
    Sincerely, SueEllen

  34. Thanks. BTW, the Purple Cherokee is one of my very favorite tomatoes. πŸ™‚

  35. Kevin,
    (I am so behind on my wsing!) Is it too late to WS annuals?

  36. We ran a greenhouse for 5 years and saved seeds to try to save money (start-up of this kind of enterprize is really expensive!). Anyhow, we wanted to grow Marmande tomatoes and the only place we could find the seeds was in California and the company would only sell in multiples of 1/4 pound. Do you have any idea how many seeds are in 1/4 pound?? Tons!! We got them and used them with excellent germination for about 20 years!!! I think the clue is to keep them dry and at a fairly constant temperature. Seeds don’t appreciate temp fluctuations. But there are some seeds that won’t keep no matter what. Experiment and have fun. Oh and we finally found another supplier of Marmandes.

  37. Anne Schomaker says:

    I had no idea I could do this with old seeds. Thank you for the information. I’ll try it on my bean seeds this week.

  38. Hi! Love your gardening tips! I share with the Horticulture group I attend. I have corn seeds..maybe 15 yrs old!..and I’ll test them along with several flower seeds friends have given me. Hopefully I’ll have luck. Something makes it hard for me to dispose of seeds or volunteer plants. Did you plant the seeds that germinated?
    Please don’t spoil your adorable beagle…we don’t want him to be overweight!! Perhaps every 5-10 responses would be better?

  39. Thank you. Wonderful post as usual, and I am so glad some of you all talked about being able to plant them. That way I can figure out if the damn flowers I am planting are weeds, or if they are actually flowers. Errr!

  40. Wish I’d seen this last week. I have a large variety of greens seeds from past years and decided to use your idea of planting them early in plastic milk cartons. Keeping my fingers crossed that they sprout. I also have an idea I want to try if they do sprout. It involves planting the seedlings in a wire moss-lined hanging basket so that they fill in all the way around it. Not only does it look great in the picture I saw, but it would provide a number of great salads all in one basket. Hoping it works for me.I love reading your articles, they’ve helped me a number of times. I live in Colorado and only have small odd spots for my vege gardening that don’t get full sun all day, so my growing season is not real long and can be a little challenging at times. I’m always looking for ideas that would help.

  41. Kevin….I think you will love Fanny and Alexander, a movie by Ingmar Bergman, if not for the story but for the opulence and decorating ideas! FYI….so incredibly beautiful.

    I’m a big fan of yours πŸ™‚


  1. […] have old seeds and do not know whether they are still viable? Test the viability of your seeds: […]

  2. […] way old testing old seeds. It seemed simple, but it left me with a few questions. I then found this one, with loads of pictures and time frames to work with. Much better! Here is what I did this past […]

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