How long can seeds of vegetables be kept and still be viable for planting in the garden?
Now is a good time to get out your seeds and take a look at the dates and storage conditions.
Seeds of plants have different shelf lives which evolved under the conditions of the origination of the plant species. The seed coat that protects the seed also determines the length of time that the seed germ can stay alive and any conditions that must be met to stimulate germination.
The quality of storage conditions before and after consumer purchase will make a difference on germination percentages when the seeds are sown.
If you are relying on a high germination rate it is best to buy fresh seeds from a reputable seed company. Packages of seeds that are exposed to sunlight, high temperatures and moisture in the store can be damaged reducing the viability and number of seeds that will be able to germinate and grow.
Leftover seeds from a growing season can be stored if packaged properly and kept under optimum conditions. The viability and life of seeds can be extended under perfect conditions of low humidity and low temperatures.
Here in Las Vegas generally the air is dry but cool temperatures will need to be maintained. Seeds should not be kept outdoors or in a hot garage during the summer months. If storing in the refrigerator or freezer a proper container will be needed to keep the moisture out.
The following quick list of seed longevity for some common vegetable seeds will help when purchasing seeds and to know when to discard old seeds. As a general rule of thumb seeds kept under dry, dark household temperatures should stay viable for at least this length of time.
Keep these dates in mind when ordering or buying seeds. If optimum storage conditions are not available; only buy what you plan to use up each year.
1 year – onion, lettuce, parsley
2 years – corn, leeks, okra, peppers
3 years – beans, peas, spinach, carrot, Chinese cabbage
4 years – beets, cabbage, cauliflower, eggplant, pumpkin, radish, squash, tomato, watermelon
5 years – cucumber, endive, muskmelon
8 years- celery
See this fact sheet “Storing Vegetable and Flower seeds” from Colorado State University Extension that gives more details on how to store seeds for maximum longevity and a comprehensive list of shelf life for vegetable seeds.