Short article on seed storage...
http://www.survivopedia.com/how-to-store-seeds-in-winter/This can be a live-or-die option, so do plan on how you will store your prepper seed bank.
Remember, pre-event, to rotate your seed stock. Keep the prior years seed, but add an new set. Seeds do not totally expire, but their viability does fall. Better to have 100 seeds, of which only 20 will sprout, than to toss them all away each year.
Some seed have a multiyear storage, but not all. Do the needed research on each kind of seed.