If you’re a frugal New England gardener, you likely have unused seeds that you’ve saved from previous years. Before the growing season gets started, it’s important to know whether any leftover seeds will germinate, before throwing them away or investing time and energy planting expired seeds.
“Many types of seeds have the potential to remain viable for years if they are kept in a consistently cool and dry place,” says Emma Erler, lead horticulturist at Kirkwood Gardens and Homegrown NH host.
Germination testing will require you to sacrifice some seeds, so if you only have a small number, you may be better off planting what you have.
Here’s how to do your own germination test:
- Gather paper towels, plastic bags, and some water — preferably in a sprayer — in a warm location.
- Start by dampening a paper towel with tap water. Use a spray bottle to moisten the towel without leaving it dripping.
- Place 10 or more seeds an even distance apart in a straight row about one inch from the top of the towel, recognizing that the more seeds you use, the more accurate your results will be.
- Fold the bottom of the paper towel over the line of seeds and then gently roll it up and place it inside of a plastic bag.
- Place the seeds in a warm location out of direct light and check on them after three to five days to see if seeds have germinated.
- End the test after all of the seeds have germinated or if you have reached the typical number of days it should take them to germinate.
If you want to calculate the germination percentage of your seeds, divide the number of sprouted seeds by the total number of seeds in the test and multiply by 100.
If the germination percentage is low, you may want to consider purchasing new seed.
If the seed is important to you and you want to try growing it anyway, start the seeds indoors for best results. The germination rate of seeds planted under ideal conditions indoors is often higher than that of seeds that are directly sowed in the garden.
You can find charts online with information on how long common vegetable and flower seeds are viable.
See you in the garden!
Homegrown New Hampshire is a collaboration between Squam Lakes Natural Science Center and NHPR.
