A seed packet usually contains more than enough seeds for planting a single season's harvest. How long do seeds last, and how do you know if they'll produce a viable crop? We're all familiar with freshness dates on foods, and packets are similarly dated. However, the date indicates when the seeds were packaged, rather than how long they will last.
Most seeds will last several years if stored in a cool, dry place. However, some seeds, like onions and parsley do not seem to last as long as others. Some seeds can germinate after hundreds of years, and even longer: Mimosa seeds in the National Museum in Paris germinated after 221 years in storage. Seeds preserved in the frozen soil of the Arctic tundra germinated after 10,000 years; scientists used radioactive carbon-dating methods to check the age of the seeds.
To determine if seeds are still fresh enough to grow, conduct a simple germination test. A great late-winter project, germination testing helps a gardener take stock of the seeds on hand, plan this year's seed orders, and organize seeds well before it's time to plant them. Best of all, this simple test reminds a gardener of the miracle asleep inside every seed.
Tools and Materials
- Paper towels
- Seeds for testing
- Re-sealable plastic bags
Seed Test How-To
1. Fold paper towels in half, and moisten with water. Place a row of ten seeds on the towel, and roll up like a jelly roll. Put seed roll into a re-sealable plastic bag; label the bag with the type of seed. Repeat with the other seeds you plan to test.
2. Place the bags in a warm place (about 70 F), such as on top of the refrigerator. Look at the germination period on the back of the seed packages; germination can take a few days to a few weeks depending on the type of seed. (If the package doesn't have any germination information, check the seeds after about a week.)
3. After the germination period, count your sprouted seeds to determine the germination rate: For example, if six out of ten seeds sprout, that indicates a 60 percent success rate. If less than 50 percent of the seeds sprout, purchase new seeds, or sow the seeds heavily for a successful crop.