Germination Testing

We always have seeds left over from previous  years’ supply. This week I want to plant spinach and head lettuce, but my new seeds won't be here for a while. So I want to use seeds that are a few years old. When they arrived, the spinach was rated at 85% germination and the lettuce at 95%. These are pretty good rates, but neither spinach nor lettuce is a terrific keeper – their germination rates go down  just a little every year. So I really need to know how well they’ll perform because I want to get these babies into the ground!

So what do I do? A germination test! It’ll tell me what percentage of these seeds I can expect to come up. What I’m actually looking for is how much extra seed I’ll need to use for this first planting. You can do this at home, too!

Here’s how it works:

I placed a folded paper towel in a zip-top bag, labeled with the plant that’s going into it. Added 20 seeds, and moistened with warm water. The whole thing goes into a dark location at room temperature – in this case, right on top of a covered flat of tomato seeds. A towel laid over the top provides the buffer they need from direct light while they’re sprouting. While these little guys are in their bags, I might open them a couple of times to let in some air. Some species have just done better for me during germ tests when they get to breathe.

I’d expect the spinach to sprout in 5-12 days and the lettuce in about a week. So I’ll start checking them after 5 days to see how many have sprouted. If I’m lucky, I’ll get something close to the original estimated rate. If not, well, I’ll be able to calculate just how much extra is needed to fill up the beds.

Want to see how the test turns out? Check back next week for an update!