Do Seeds Expire?
Many people see a year written on the back of a seed packet and think this is an expiration date. While seeds do lose viability over time, they don’t have standard expiration dates like you would see on packaged food. Seeds are living things. They are able to be stored for several years if kept under the right conditions.
How Long Do Seeds Last For?
Exactly how long you can save a seed depends on what it is. Different seeds have different storage capacities. Below are some of the most common types of seed to save:
- 1 Year - Onions, parsnips, parsley, and spinach
- 2 Years - Corn, Peas, Beans, Chives, and Okra
- 3 Years - Carrots, Leeks, Asparagus, Turnips, Rutabagas
- 4 Years - Peppers, Chard, Pumpkins, Squash, Watermelons, Basil, and Artichokes
- 5 Years - Brassicas, Beets, Tomatoes, Eggplant, Cucumbers, Muskmelons, Celery, and Lettuce
These values are simply an estimation. To know if those extra seeds you have kept in a bucket are still good just do a germination test. To do this, wet a paper towel and roll up 10 or more of one type of seed. Keep this damp paper towel full of seeds in a plastic bag.
After 5-14 days you should be able to count how many have germinated. The results will help you know how well you can rely on that batch of seed. Plant at a rate you feel confident in. For example, if only 5 of 10 seeds germinated you may want to plant twice as many seeds as you want to grow to maturity since half of them likely won’t germinate.
Why is there a year stamped on my paper packet?
How seeds are stored make a big difference on how long they will stay viable for. The biggest influence is the temperature and type of container the seeds are kept in.
Looser packaging such as paper packets tend to leave the seed more susceptible to a changing environment. For this reason paper packets are required to have a “packaged for” year. This year stamped on the packet is often confused as being an expiration date.
The reality is, this seed is just fine to use for years to come. The same seed may also come packaged in a sealed plastic or mylar bag which will better preserve your seeds from external environmental factors.