The Doomsday Preppers of New York

I'm curious if home garden farming is big among the "preppers" - but then I think that planning a more self-sufficient food supply is only valuable to non-nuclear/chemical warfare doomsday thinking (such as the author's economic collapse bias).

That leads me to wonder if the kits the article goes over would reveal which scenario is presumed by the owner through deductive reasoning... Does anyone keep a personal seed bank? Or do most people assume the apocalypse will have a relatively brief duration and then the supermarket will have fresh produce again?