Shelf Life of Garden Seeds

Vegetable Seeds

• Vegetable seeds usually last anywhere from one or two years for corn, onion, parsnip and parsley, and up to five years for vegetables such as cucumber, endive and muskmelon.

Flower Seeds

• Delphinium seeds only survive about a year, and aster, phlox and sweet pea for two years. However, some seeds, such as carnation, hollyhock, nasturtium and zinnia can last five years.

Factors Affecting Shelf Life

• Moisture and temperature are the two factors that most influence how long seeds will remain viable. Low moisture and a temperatures between 35 and 41 degrees Fahrenheit help seeds to last longer.

Extending Seed Life

• Moisture can be removed from seeds by drying them outdoors or in an oven for about six hours, being careful not to exceed 100 F. Properly storing seeds can also extend the shelf life. They can be packed in a moisture-proof container, preferably with a drying agent included, and kept in a refrigerator.

Testing Viability

• You can test your saved seeds before planting to make sure they will grow. Roll up several seeds in a double layer of moist paper towels. Place in a glass container or plastic bag, and keep moist. Check after the average germination time for that plant to see what percentage of the seeds have sprouted. This will tell you if the seeds are still viable.