How long do garden seeds last?

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Last Updated: 
February 19, 2003

CORVALLIS - Home gardeners are often frugal by nature. They save leftover garden seed from one year to the next and so forth. How long do seeds last?

It depends on how you keep the seeds and what kind of seeds they are, explained Oregon State University vegetable researchers Deborah Kean and Jim Myers.

If seeds are kept dry, they last longer than in more humid conditions.

"Seed saving on the west side of the Cascades is more difficult than on the east side where it is drier," said Jim Myers, a vegetable breeder at OSU.

Some types of seeds are naturally more short-lived than others.

"Parsnips, spinach, lettuce and the alliums have the shortest seed life," said Myers. "And there may be some correlation with oil content of seeds with seed life. Generally, the higher oil content seeds decline in germination more quickly."

Seed is best stored through the winter at 50 degrees, at 50 percent humidity. A good way to store unused seed packets is to place them in a sealed jar with a desiccant such as powdered milk or rice at the bottom (to absorb moisture). Rice can be reused again as a desiccant if you dry it in the oven at a low temperature, said Myers. Store your seed jar in the refrigerator or a cool area, such as a basement.

Minimum seed life for common homegrown vegetables and flowers are given below. These seed life spans reflect no special care taken. If you keep your seeds dry and cool, you can expect many of them to last longer than the time periods indicated here, especially beans, peas and corn.

Bush and pole beans - two years

Beets - two years

Broccoli, Brussels sprouts, cabbage, cauliflower, and kohlrabi - three to five years

Carrots - three years

Collard, Kale - three to five years

Sweet Corn - one year

Cucumbers - three years

Leeks, onions - two to three years

Lettuce - three years

Melons - three years

Oriental greens - three years

Parsley - two years

Parsnips - one year

Peas - two years

Peppers - two years

Radishes - four years

Rutabagas - three years

Spinach - one season

Squashes - three to four years

Swiss Chard - two years

Tomatoes - three years

Turnips - four years

Flower seed - annuals are generally good for one to three years; perennials for two to four years.

Author: Carol Savonen
Source: Jim Myers, Deborah Kean