QUESTION: How long do seeds last for planting? I have some old seed packets. — Lina V
ANSWER: Seed packets should be printed with the year for which they’re intended. For example, they might say “packed in 2019.” Generally, you can trust an opened packet of seeds up to a year, and unopened packages of seeds can last longer than that. There are also variations in shelf life among different types of seeds. For example, onion seeds rarely last longer than a year, but lettuces may last five years or more. This article from the Farmer’s Almanac has a table that can show you how many years to expect your seeds to last depending on what they’ll grow.
To determine how good your seeds are when they’re more than a couple of years old, you can conduct a simple germination test. Moisten a paper towel and fold your sample seeds inside, then slip it into a plastic sandwich bag. Do not zip the top of the bag closed. Label the front of the bag with the seed type, then let your test run by allowing the seeds to sit inside the sandwich bag in the warmest spot in your house. Begin checking after five days, taking a look daily to check for sprouting. Viable seeds should start growing by the tenth day. If fewer than one third of your test seeds sprout, you’ll probably want to go ahead and replace your stock.