I was digging around in my little Seed Fridge to retrieve my Herb/Tomato/Pepper seeds, and in the very back I found purpurascens seeds I had saved from Fall2020. That's only 1½ years and they have been in cold storage all the while. They look good to me. I am soaking a few in distilled water/on heat mat for testing, but I think they look good. I also found Showy milkweed seeds I had saved from Fall2018 ( 3½ yrs). Doing the same with them in the water soak/on heat mat. These look good also. If you would like to try some, please send two(2) USA Forever stamps with your mailing address. Sorry, USA only. No need to send an envelope as I prefer to use discounted-after-Christmas Cards. I feel it keeps the seeds much safer going thru the postal system. TreeMail me for my address if interested in trying these seeds. I cannot guarantee seeds will germinate but it's worth a try. As I mentioned, they look good to me and I grow a lot of milkweed each year!