Seeds do not have a strict expiration date; rather, they have a "sell-by" date. The dates on seed packages are guidelines to help you know when your seeds are getting older, but it does not mean you need to toss them immediately. Every plant variety is different, and some seeds last longer than others. Most SUFLORYES seeds, if kept in a cool, dry place, will remain viable for 2–3 years. If you are ever unsure about their germination, you can test a few out first by growing microgreens or starting them in a small pot.