Thanks. I didn't think of the (mentioned) Seed Banks originally, but I've seen pictures of (supposedly) a real seed bank somewhere in Denmark or Norway. Then searching "world seed bank" Bing returned this:
https://www.bing.com/search?q=world+...ZI&form=MOZTSB
22 years is impressive! My best is about 10 years, but then I don't know how old the seeds were when I got them -- presumably only a few years at most.
Just curious about this stuff.