How to Test Seed Viability – Don’t Toss Those Seeds!

posted in: Gardening | 3

I don’t know about you, but I have more seed packets than I know what to do with. As I was organizing seeds last weekend, I found some that were almost 10 years old! (Hence, why I started my seed organization project in the first place!) While 10 years is a bit extreme, and those did go in the trash, many seeds remain viable much longer than the “plant before” date on the packages.

So, how do you know which seeds to keep and which to toss? I’ll show you how to test seed viability the easy way.

How to Test Seed Viability

What You’ll Need:

  • old seeds
  • paper towels
  • water
  • ziploc bags
  • marker


1. Dampen a paper towel. Make sure it is thoroughly saturated, but not dripping. I just wet it, squeeze it out and flatten it.
test seed viability

2. Lay out a small sampling of seeds on the paper towel. I like to do 10 at a time, but you can do however many you want. I wouldn’t do less than six, though, because you want a decent sampling. Be sure to only use one variety per paper towel, so you’ll know which packet they came from.


3. Fold the paper towel over on top of the seeds and press down lightly to ensure each seed remains damp.Carefully place your paper towel seed packet in a ziploc bag and seal it.


test seeds viability
4. Label the bag and set aside out of direct sunlight in a warm spot. Check your seed packet for germination times (or check online) and make a note of when to check on them. I’ve chosen to test green pepper seeds that I saved from my own plants three years ago. Germination times for peppers can be anywhere from 8 to 18 days, depending on temperature, so I’ll have to wait awhile to test seed viability for these ones.


Label Seeds for Testing
5. Check on your seeds every couple of days to make sure the paper towel is still thoroughly damp. If it is starting to dry out, mist it gently.


6. After the germination time is up, remove your seeds from the bag and check to see how many have sprouted. If they haven’t all sprouted, I usually put them back for another two days and check again.


That’s it! You’re done! I generally keep anything over a 60% germination rate. You could wait until you’r ready to plant to do this, and just plant the ones that sprouted if you want. I like to test them earlier, though, so I have time to order more seeds if I run into some that are complete duds.


Do you test your seeds, or do you just plant them and hope for the best?


P.S. This post is linked up with The Homestead Blog Hop and From the Farm Hop.

3 Responses

  1. I plant mine and hope for the best 🙂 This seems like a much better way!

    • I do too for most of my seeds, especially the ones that germinate quickly. For those that germinate really slowly, like peppers, I like to test them first if they are old. That way I don’t waste 2 weeks of that valuable time waiting for duds!

  2. […] are expired, but quite often they remain viable much longer than the plant before dates. I’ll test seed viability on a few before I sow […]

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