Seed longevity: Are my seeds still good?
Let's talk about seed viability (longevity).
Different seeds stay viable for different lengths of time. You can find graphs all over the Google-verse telling you exactly how long you can expect your pack to last. But I'm going to let you in on a secret: if you store your seeds even close to correctly (cool, dark, dry), you can throw those graphs out the window.
For example, according to this graph from Iowa State University, onion seeds should only last one year. When I tested my three year old seeds last month however, they had at least 90% germination.
Right now I still have a LOT of seeds, over 200 packs in fact. Over the last couple of years I've been whittling it down from 500+ (the whole reason I started this nursery business in the first place!). Since most of these seeds are from at least that long ago I figured this would be a good year to do some germination testing.
Germination testing is super easy.
1. Get a piece of paper towel
2. Write the name of the seed on the paper towel in permanent ink
3. Wet the paper towel thoroughly (I usually pour water onto it on the counter)
4. Put 10 seeds on the wet towel and fold it up, enclosing the seeds in the wet towel
5. Put the folded towel in a plastic baggie, tupperware, whatever.
6. Set the baggie somewhere warm-ish, like on top of the fridge.
After a few days, start checking your seeds by gently unfolding the wet towel. If you don't see any roots starting to come out of the seeds, fold it back up and check again in a couple of days. I usually expect older seeds to take a little extra time.
(The back of the seed packet should tell you approximately how long the variety you're testing takes to germinate, so use that as your guide as to how often you check your wet towel wrapped seeds.)
After the germination period is over, unwrap your seeds and count how many have sprouted. Since you used 10 seeds, the calculation is easy; if eight seeds sprouted, you have 80% germination.
The way I start most seeds allows me to get away with a very low percentage for my annuals. Perennials require a bit more decision making. More on that later.
So far I've tested onions, beans, peas, lettuce, tomatoes, peppers, parsley, and a few other things. My seeds are well cared for, so germination has been good. I just did spinach tonight, so we'll see how that goes.
Most of these germinated seeds will be given to the chickens and not planted since it is much too early for them. I've got to check early so that I can order anything that doesn't germinate before it is actually planting time.
What seeds are you testing this year?