How long do garden seeds last?

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, said Jim Myers, an Oregon State University vegetable breeder.

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 Myers.

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