Whether you are saving seeds from your own garden plants or have leftover seeds from the year before, knowing which seeds are still good for planting is necessary. Testing the viability before starting your spring seed starting ensures you begin enough transplants to fill your vegetable garden or ornamental beds without having to rush out and buy nursery stock at the last minute. Check the seeds germination rates a week or two before you plant to begin your spring garden.
Look the seed over before checking viability. Discard any damaged or broken seeds and those with visible mildew or mold on them.
Stack three paper towels on top each other and moisten them until they are as damp as a wrung-out sponge. Wring out any excess moisture but avoid tearing the towels.
Place 20 to 50 seeds from one plant variety on the paper towel, spreading them out so they aren't touching. Roll the paper towel into a loose tube and place into a plastic bag and seal.
Place the bag in a warm 70 to 80 Fahrenheit room. Check for germination after three days. If no germination is apparent, check daily until germination occurs.
Wait seven days after the first seeds germinate. Open the bag and roll out the paper towel after the week is past. Count the amount of germinated seeds on the paper towel.
Divide the number of seeds that germinated by the number originally placed in the bag to get the germination percentage. Plan the amount of seeds to plant by this number, for example if 50 percent of the seeds germinated plant twice as many seeds as seedlings needed.