Food is mostly the same thing, over and over, and you buy it ready to eat, or nearly so. Very few still raise their own food, and even fewer know that many edible plants are perennial. I will write on vegetable food plants, hardy in zone 3 or 4, that come up every year or reseed themselves: Shoots, tubers & bulbs, cooking greens, and salad greens. [Burpee calls the Spokane area zone 5.] My sources will include books, magazine articles, and websites. If you know of other edible perennial plants in each category, please leave a comment!