Seeds lose up to 30% of their viability each year
It’s easy to determine the viability of seeds you’ve either saved yourself or gained in an exchange. This simple germination test involves the seeds in question, a paper towel, water, a plastic freezer bag and a warm spot.
Begin with dried, cleaned seeds. You say you’ve never saved seeds and want to know how? The International Seed Saving Institute maintains an excellent online resource. Here’s a quick checklist:
Save Your Own Seeds
- Harvest seeds from fruiting crops (i.e. tomato, pumpkin) when the fruit is quite ripe but before it has gone by.
- Collect seeds from beans, peas and quinoa when the plant (leaves and pods) are dry.
- Gather small seed capsules (i.e. mustard, basil) before the seed head opens or drops.
- Clean and dry all seed completely before storage.

sort out & discard broken, damaged or concave seeds

these seeds were washed and are now drying
Test Before You Sow Germination Test
Step one
Dampen a paper towel.
You could run the towel under the faucet, but then you’d need to let excess water drip off and you might tear the towel. Some would wet the towel using a spray bottle, but I’m too impatient for that. I put a quarter cup of water into a serving platter and dredge the towel through that, letting any excess run back onto the platter.
Step two
Lay the damp paper towel on a large cutting board or on your counter, and set the seeds on one half. I usually use a dozen seeds. Some folks use more, some use as little as ten.

lay the seeds on half the paper towel, fold remaining half over top
Step three
Fold the paper towel over the seeds, and insert the towel, flat, into a air-tight sealable bag. Write the seed variety and date on the bag, especially if you’re testing more than one variety.

this sealed bag will sit atop my refrigerator until the seeds sprout
Step four
Place the sealed bag in a warm spot, say, on top of your refrigerator or water heater.
The most rapid seed germination occurs when temperatures remain consistently between 70 and 80 degrees. Some people place the bag near a wood stove or heater vent, but I think those locations experience too great a temperature variance.
Step five
Check your little darlings at regular intervals (say every two or three days). Most viable seeds will germinate within three weeks; some will sprout in as little as two days. I place heat loving seeds test baggies inside a lidded stoneware bowl to help retain heat.

these home-saved Oaxacan green dent corn kernels germinated at 100%
Calculate the germination rate when the majority of the seeds have sprouted and several days have passed since the last sprouting. A 70% or greater germination rate indicates viability. A germination rate between 69-39% isn’t great, but it’s no reason to toss the seed. I plant these seeds right away, and usually ‘over’ plant, ending up with more seeds in the ground than normal, as fewer will germinate. And if they al sprout, well, yay. I feed thinnings to our chicken.
I don’t mess with seeds with a 30% or lower germination rate, as plants resulting from old seeds will likely be weaker and thus prone to disease and insect attack. Yuck.
One more thing about seed germination: when deciding whether to use older seeds, it’s wise to note that different seeds have a longer shelf life. Corn, for example, is best planted within two years while other vegetables (notably cucurbita family members) last far longer. This page has a good array of seed shelf life data.



































































