Do you have a seed stash tucked away? I certainly do. It’s rare that I use up all the seeds I buy in any given year. When I have some left over, I put them away for next year’s garden.
It just seems so wasteful to throw seeds out, doesn’t it? And, of course, if you harvest and save your own seeds from year to year, then you definitely have a stash, too.
Whether your own stash was purchased or saved from a previous harvest, those seeds won’t be viable forever. The longevity of seeds depends both on which cultivars they are and how they’re stored. Some seeds — including leeks, onions, parsley and parsnips — will last a year at best. Others will remain viable up to five years after they were harvested, and possibly even longer if they’re stored in the right conditions.
Best Method of Seed Storage
Seeds are best stored in cool, dry locations. A general guideline is to keep the combined temperature and humidity level under 100. As an example, the ideal temperature for seed storage is about 40-45 degrees Fahrenheit, which would allow for a maximum humidity level of about 50 percent. To keep your seeds dry, store them in an airtight container. Glass jars with rubber seals on their lids, like baby food or home canning jars, work best. If you’re concerned about moisture within the jar, you can add in a desiccant such as rice.
Keeping the seeds in the fridge or freezer is an excellent way to maintain perfect storage conditions. Keep in mind that frost-free fridges and freezers work by drawing out moisture, and can seriously dry out seeds. However, as long as your seeds are in an appropriate container, they shouldn’t become damaged.
Freezing seeds properly can exponentially prolong their longevity. After all, seed banks like the Svalbard Global Seed Vault count on freezing to keep their seeds viable for centuries. The home gardener shouldn’t expect her own seeds to last quite as long in a home freezer, given the strict scientific protocols and optimal conditions of the Global Seed Vault. Still, frozen seeds should remain viable longer than seeds stored at room temperature.
8 Seeds That Easily Store for 5 Years
While storage methods have a big impact on seed longevity, the type of cultivar also makes a difference. Some of the longest-lasting seeds are members of the cabbage family (Brassicaceae), but there are eight different types of vegetable seeds that will remain viable for about five years, even if not frozen:
Viable and Vigorous Seeds for Healthy Plants
For the healthiest and best-producing plants, you need viable, vigorous seeds. Viability is basically the rate at which seeds sprout or germinate. If, in a sample of 10 seeds of the same cultivar, eight sprout, the germination rate is 80 percent, which is highly viable. If, however, only two or three seeds in that sample sprout, the germination rate is 20-30 percent, and the viability is low.
In addition to viability, the vigor of seeds is an important consideration. Viability is generally measured under optimal conditions. But vigor measures how well sprouted seeds perform under less-than-optimal conditions (e.g., outside in the garden). Seeds need to be strong and healthy to flourish in variable weather conditions and in soil that may be less than ideal.
As seeds age, they decrease both in viability and vigor. They may lose their ability to sprout at all, and those that do sprout may just not have the strength to create a healthy plant. It’s easy to test a seed’s viability, but somewhat more difficult for the home gardener to determine a seed’s vigor. However, by keeping track of how long your seeds have been stored, you can use the list above to determine how well your seeds are likely to perform without bothering with tests.
If you’ve had any of the listed seeds stored for five years already, it would be best to get those planted this year, for healthy plants and a bountiful harvest.
What’s your personal record for planting seeds that have been stored a long time? Share your thoughts in the section below: