Germination Testing — Do It Now to Get Ready for the Season

Now is a great time to evaluate your seeds. It’s a fun rainy (or snowy) day project to pull out the box and flip through the packets. What did well? What did poorly? What can’t you wait to plant again? Perhaps most importantly, what can you take to the seed swap and be sure your gardening friends will be getting good seed?

As you hold an older packet in your hand, one big question comes to mind: Are these seeds still viable? Three years is a good general cutoff date, but some will last much longer. And if you haven’t been as careful as you should have in storage, they might not sprout. So how do you know?

There’s a pretty easy way to find out if the seeds are still good: do a germination test. Here’s one way to do it, in 5 steps. As an example, I will use a test that I began today.

1. Count out a good quantity of seeds. In this test, I used Black Spanish Radish (Raphanus sativus) from 2020. This was the last of a large bag tied up in the garage. I shelled them from their pods until I had 100 seeds.

2. Place the seeds on a moistened paper towel. This will give them a place to germinate.

3. Fold over the paper towel and insert it in a large zippered plastic bag. Lay it flat in a warm place out of the way. I use the top of my refrigerator.

4. Monitor the project daily for the next two weeks. Don’t let the paper towel dry out–the seeds need the moisture to sprout. Just open the bag and sprinkle a little water on the paper, or squirt it with a mister. Keep it moist, but not too wet.

5. Some seeds sprout within a few days, while others can take up to two weeks. When you see the first ones sprout, wait a few more days. Then open it up and count the little green shoots. The seed would be considered viable to share if more than 60 percent of the seeds sprout in your test. A higher number would be much better. At 50 percent or below, it’s best to just toss those seeds on the compost heap and buy (or swap for) fresh seed.

I’ll update this post with the results of my test, so check back in a couple of weeks. Meanwhile, start your own germination test–and post your results to our Facebook page!

Update: 60 Percent Germination

Well, after 10 days I pulled the plastic bag from the top of the fridge and saw some pretty good sprouting. Not great, but good. Turns out my Black Spanish Radish seeds are right on the edge of the viability: just over 60 of the 100 seeds sprouted, a 60% germination rate. I will share the seeds this year while letting people know to sow a little more heavily, and then compost any leftover seeds after this season.

Germinated seeds pushed at the paper towel and peeked out.
Check out the amazing root system on this little radish sprout!

There are other methods and of course advice varies. Here are some germination testing resources:
https://extension.illinois.edu/blogs/ilriverhort/2017-02-03-test-seed-viability

https://www.newstribune.com/news/2021/jan/31/Ask-a-Master-Gardener-Germination-test/

https://www.southernexposure.com/how-to-test-germination/

https://www.highmowingseeds.com/blog/how-to-do-a-quick-germination-test-at-home/

Learn, Connect at Our Seed Swap

Want to learn how to start seeds, build a worm bin or protect your apples from pests? That information and much more will be available from the Seed Lending Library and our community partners at the Great Seattle Seed Swap on Saturday, April 16, 11 a.m. to 1 p.m.

Joining us at the Swap will be:

  • Seattle Tree Fruit Society will be on hand with bags of nylon “footies” for sale. These protect apples from codling moth and apple maggot, two of the worst pests in our orchards. They also will have a limited supply of bare-root strawberry plants for sale.
  • Sustainable Ballard will be at the swap with information about their tool library and their annual Edible Garden Tour, a truly inspiring event.
  • Tilth Alliance is sending a Master Composter to talk to attendees about composting techniques and tips. They show you how to build and care for a worm bin, so you can turn your kitchen scraps into fertilizer. He may even bring a worm bin for show-and-tell.
  • PNA Tool Lending Library will be in attendance too, showing an array of garden tools and talking about how to use the tool library.

Also, a leader of the King County Seed Lending Library will hold a short workshop on seed starting techniques.

Sign up on our Facebook event page and we will see you at the Swap!

Join us at the Seed Swap!

Interesting lettuce? New tomato? Sunflowers for solidarity with Ukraine? Join the Seed Library for the return of our Great Seattle Seed Swap! It’s our first since 2019, and we can’t wait to share seeds with you.

The swap will be Saturday, April 16, 11 a.m. to 1 p.m. at the Phinney Neighborhood Center, 6532 Phinney Ave. N., in the Community Hall of the Brick Building.

Recent donations from the Organic Seed Alliance of their “Teddybear Sunflowers” and from High Mowing seeds will provide new choices for seed-swappers to try this year.
OSA’s Semi-Teddybear Mix. Photo by Bill Thorness.

See our Facebook event and let us know you’re coming!

Do you have seeds to share? Here’s a guide to our preferences for seed-sharing:

  • Share only seeds of edible plants that your fellow gardeners would grow from seed, such as annual vegetables, herbs and edible flowers.
  • If donating packaged seed, it should be organic or open-pollinated, plant types that will produce seed true to the stated variety. Heirlooms are by definition open-pollinated.
  • If donating home-saved seed, please winnow and clean it off the stems or stalks as much as possible and bring only the seed.
  • If you can’t clean it in advance, plan to spend some time cleaning it the swap. We will have screens and buckets available.
  • All shared seed should be fresh, within three years of purchase or saving.
  • Label all seed donations with seed type, variety if known, and year it was grown/saved.
  • Bring envelopes and a pen to store and label your new seeds.

Look forward to seeing you in person soon!

Winding Down a Quiet Year

Hi friends of the Seed Library! Our quiet gardening season is now at an end. The seeds have been retired to their winter home in a cool, dark back room.

It’s been a tough year to share seeds, with fewer open hours and no chances to get together. We hope that next year will see some return to normalcy. May the autumn bring you peace.

2021 Update: No Swaps, but Seeds Available

Hello gardeners and seed-swapping friends. We have a happy/sad message for our community.

The sad news is that we won’t be holding any seed swaps this year due to the coronavirus. That is probably not a surprise to most of you.

The happy news is that seeds are available in two of our locations, and more locations may reopen in the near future.

Borrow Seeds in NE, NW Seattle

Two KCSLL branches are resuming seed sharing in their respective locations. Both the NE Seattle branch and the NW Seattle branch are located in their community tool libraries, which are now reopened with limited hours.

— The NE Seattle branch is open Tuesdays and Thursdays 5-8 pm and Saturday 9 am-noon.

— The NW Seattle branch is open Saturdays 9 am-1 pm. 

— Both branches are limiting the number of simultaneous visitors and requiring coronavirus precautions such as wearing a mask and observing a 6-foot social distancing rule.

Due to limited display space, the NW Seattle branch is only offering seeds of crops that can be sown now. Seeds of warm-weather crops like tomatoes, peppers, beans and squash will be made available in early spring.

Donate Seeds

Seeds can also be donated at these two locations, but please observe these guidelines: pre-clean any homegrown seed, put it in a compact package, and label it with the crop, variety name, and year saved. Partial seed packets may be donated as well; please tape them shut.

Thanks to Territorial Seed Company for sending this lovely donation last fall. Look for their colorful packets of 2019 seed in our offerings this year.

Please continue to watch this blog and our Facebook page for updates on seed availability at other locations or expanded hours. Current location hours and a link to spreadsheets of available seeds at these two branches are available on our Locations page.