If you’re like me, there’s a good chance you’ve ended up with packets of seeds that have passed their expiration date. Rather than throwing them out and buying new ones, a simple germination test can help you determine if they’re still viable. This test is a practical solution to ensure you don’t waste potting mix, time, or space by sowing seeds that may not sprout.
Why Test Seed Viability?
A germination test is useful if you have seeds that are past their use-by date or if you’ve misplaced the seed packet and can’t recall how long they’ve been in your storage. While it’s generally unnecessary to test seeds that are within their use-by date, they may not germinate if they’ve been improperly stored—exposed to high temperatures or humidity, for example. A germination test will help you verify their viability.
If you’ve saved your own seeds, a test can also ensure that your storage conditions were optimal or that your saving technique was successful, especially when it comes to new plant varieties or seeds nearing the end of their shelf life.
How to Perform the Paper Towel Germination Test
Testing seed viability is simple and doesn’t require specialized equipment. All you need is a paper towel, a plastic bag (such as a sandwich or freezer bag), a small container, and a spray bottle to moisten the towel.
- Prepare the Materials: Lay out a sheet of paper towel and lightly mist it with water. Ensure the towel is moist, but not soaking wet. Choose at least ten seeds for the test; ten seeds make it easy to calculate germination percentages. For very small seeds like lettuce or onion, it’s easier to sprinkle a pinch of seeds on the towel and count them once they’ve sprouted.
- Place the Seeds: Space the seeds evenly across the top half of the towel. Then, fold the towel over the seeds to ensure they’re enclosed in moist paper on both sides. Roll the towel into a tube.
- Seal and Label: Place the rolled towel in a plastic bag, leaving it slightly open to allow for air circulation. Label the bag with the seed type and variety, as well as the test date. Store the bag in a warm area that matches the ideal temperature for germination.
- Monitor and Mist: Check the seeds regularly and mist the towel with water if it starts to dry out. Some seeds, like celery, require light to germinate, so simply place them on the towel on a plate and leave them uncovered.
Checking Germination and Interpreting Results
The time required for seeds to germinate varies, typically within a 7-10 day window for peas and beans, or 6-8 days for radishes. Begin checking for sprouting at the start of the germination window and continue daily checks until the last expected germination date.
After the test period, count the number of sprouted seeds. If 7 out of 10 have sprouted, you have a 70% germination rate, which is quite good. Anything above 50% is acceptable, but if less than half of the seeds germinate, it’s best to replace them. For most crops, if there’s no germination after two weeks, consider getting fresh seeds.
What to Do with Sprouted Seeds
If the seeds have sprouted, don’t throw them away! You can plant them right away for an early start, or you could eat them as sprouts or microgreens. Many leafy vegetables and herbs make delicious sprouts. While ten seeds won’t provide enough to satisfy a meal, it’s a great way to taste test varieties and enjoy some fresh homegrown greens, especially during winter.
This simple germination test ensures you’re using viable seeds, saves you time, and prevents waste—while also giving you an early taste of your gardening efforts!