How to Determine the Quality of your Vegetable Seeds

Crops only grow to harvest from good-quality seeds. If you had great results one year, you may save seeds from that harvest in the hopes of future success. However, you should test those seeds for viability.

Confirming seed viability won’t guarantee success, but it will give you an idea as to how well that seed will perform in the field. Some seeds remain viable for a year, and others maintain vigor for three or more years. If you want to prepare for an efficient planting season, then consider these steps to check the average germination rate of your seeds.

Seed age

This table will give you a general sense of how well certain seeds age.

Plant Storage period
Fennel 1 year
Parsley 2-3 years
Tomatoes, Beans, Peas, Carrots, Onions, Celery, Beets 3-4 years
Peppers, Spinach, Radishes, Lettuce 4-5 years
Cabbage, Eggplants 5-6 years
Pumpkins, Zucchini, Watermelons, Melons 6-8 years


Water test

Choose around 20-30 seeds and soak them in a container of water for 15 minutes, then examine their positions in the water. Floating seeds are likely dead or dormant due to disease or fungi. Seeds that sank may yet take root. This test only gives you a rough idea, so we recommend combining it with one of the following.

Paper towel test

Place 10-12 seeds on a damp paper towel, then cover them with another paper towel. Make sure they have some space between them. Put the bundle in a plastic bag and leave the bag in a warm place with no direct sunlight. Check them once a day, and make sure the towel stays moist but allows some air circulation. The seeds should start germinating between three and 10 days. After the tenth day, count how many sprouted. If more than half germinated, then you can consider your seeds viable for planting. If you get fewer than five, then you probably should dispose of those seeds and plant another batch.

Plastic container test

This easy test resembles the paper towel test. Put a couple of moist paper towels in a plastic container and the seeds on the towels. By closing the lid, you’ll retain the humidity of the towels without smothering the seeds. Germination depends on the plant, so check every day. Still, if you set up the test correctly, you should see results within five to 10 days. If you don’t, then you need new seeds.


Make sure you carry out your tests carefully. It’s easy to make a mistake and throw out perfectly good seeds because the towels didn’t stay damp or the seeds lacked good air circulation. And remember that your tests and their results can’t duplicate your field conditions. Every seed is different and needs its own type of nurturing, but even the best seeds must bow to Mother Nature.

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