Pre-Sprouting Seeds to Determine Germination Percentage

Storage Conditions and Examination

• Seeds remain viable longer if they are stored in a cool, dry place. A closed jar in the refrigerator is the best storage location. Before starting a germination percentage test, consider how and where the seeds were stored and look at them closely. Seeds that got wet, sprouted, then dried, moldy seeds and seeds partly eaten by rodents or insects will not grow. Throw those seeds away.

Testing Viability

• To test viability, moisten a paper towel, place 10 to 20 seeds on it, roll it up and place it in a plastic bag labeled with the plant's name. Keep the bag at room temperature. After three days unroll the paper towel, count the number of seeds that have germinated and return it to the bag. Keep checking for at least two weeks or until all the seeds have sprouted. Moisten the paper towel if it starts to dry out. Divide the number of seeds that sprouted by the number of seeds you started with and multiply by 100. This is the germination percentage.

Using Germination Percentage

• The percentage of seed that sprouted in the paper towel is approximately the same as the percentage of seeds that will sprout when you plant them. Plant according to the directions on the package if the germination percentage is 80 or more. If it is 50 to 80 percent, plant the seeds more thickly. If the rate was less than 50 percent, you may want to buy new seeds. If it is a rare or difficult-to-find variety, it might be worth planting even if the percentage is lower than 50 percent.

Germination Percentage Standards

• Federal and state governments have set minimum standards for vegetable seed viability. These percentages vary from 50 to 80 percent. Seed companies test their seed before packaging to determine if it meets the minimum requirements. Reputable seed companies will only package seeds that exceed the minimum. Check the date on the seed packet. Seed packaged for the current year should meet the minimum standards. There are no federal standards for flower seed rates, but some states have standards.