I have a list somewhere that tells the average viability of most seeds. Corn is the shortest at 2 years. Most others range between 3-6 years, but the time can be lengthened with vacuum pack and freezing.
Course those long term survival seeds you see advertised are another story. I only plant heirlooms, and I save my seed each year. I also order at the end of year sales when they have the combo packs really cheap.
Thank you; see post 35.