like others mentioned..if kept in cool dark dry places they keep for years...i have seeds ive made in my collection back to 2014,,,just poped a couple recently for one my side projects and they doin well...just because they didnt pop doesnt mean they not viable..lot of time its the shell casing being hard...sometimes ya have to help em out..use some sand paper or an emery board for nails to skuff em up so moisture can get in to make em pop open..sometime when ya have some that wont pop..before u toss em..break em open see if theres white inside seed..that will tell ya if it WAS good and may have needed help...GL