Garden Seed Testing | The Old Farmer's Almanac

Garden Seed Testing

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Did you save seed packets from prior gardening seasons? Here is a system to test your garden seeds and see if they can be used for the next gardening season.

Ideally, you kept the seed packets in a dry place without humidity. Some folks keep the packets in a container in their refrigerator. When you are ready to test the seeds:

  1. Just wet a couple of paper towels with warm water, wring them out, and carefully spread them in the bottom of a glass baking pan.
  2. Make rows of seeds on the paper towels, writing down each variety o a corresponding piece of paper as you go.
  3. Put ten seeds in each row (so you just have to add a zero to the number that sprout to get the percentage of germination), but just use five seeds if you do not have many seeds left in a packet.
  4. For tiny seeds, do not worry about counting; just use a smear and when they sprout, estimate the percentage of germination.
  5. Get rid of packets with virtually no seeds left; get rid of seeds that you do not want to grow again.
  6. In making the rows of seeds, separate similar ones so that you don't get them confused.
  7. After all the seeds are laid out, put a piece of plastic wrap over the pan, make sure it is sealed all the way around and—being careful that the seeds do not roll—put the pan on top of the refrigerator. 
  8. Leave seeds for a week, remoistening with water in a spray bottle if the plastic wrap comes undone and the towels dry out.
  9. Then check germination rates. Get rid of any seeds that do not germinate at a rate of at least 50 percent.

How Long Do Seeds Last?

Testing seeds, as outlined above, is a good way to see for yourself which ones remain viable for five years or more and which ones won't make it to the next growing season.

Storage conditions greatly affect longevity; in general, seeds that have been kept cool and dry will do better than seeds that have been stored where it is hot and dry.

Reputable seed companies house their seeds at around 50°F and 50 percent humidity. 

Saving Seeds

To learn more about seeds and tricks for saving your own, here's a quick primer on the benefits of saving your vegetable seeds.

You may also find it interesting to learn how to harvest the most-common garden seeds. See our “Quick Seed-Saving Guide for Beginners.”




About The Author

Catherine Boeckmann

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana. Read More from Catherine Boeckmann

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