seeds
Seed viability
Last reviewed 2026-10-04
Seed viability is the ability of a seed to remain alive and capable of germinating when it receives suitable moisture, temperature, oxygen, and other cues. Viability is not the same as fast emergence or strong seedling growth. A viable seed may still be dormant or need a special treatment.
What it means
Age, storage temperature, moisture, oxygen, damage, and species all affect viability. Seed packets often state a test date or sell-by date, but those dates are not a universal expiration point. Properly stored seed can remain viable longer, while poor storage can reduce viability quickly.
How it affects the garden
Test questionable seed before sowing a whole bed. Count how many seeds produce healthy sprouts, then use the result to adjust the sowing rate. Store seed in a cool, dry, stable location and keep packets labeled. The seed germination calculator can turn a test percentage into a practical rate.
Example
If 18 of 20 seeds produce healthy seedlings in a test, the observed viability under those conditions is 90 percent. That result does not prove every seed will germinate in cold, wet garden soil.
Common confusion
Viability means alive and potentially able to germinate. Germination is the process of growth beginning. Vigor describes how quickly and strongly seedlings emerge.
Sources
Colorado State University Extension explains seed viability testing and storage factors.
