Yesterday we harvested about 100 lbs of Jerusalem artichokes from a single, partial row of the Potato Patch. A mere 25 feet of row yielded all this, almost five pounds of food per linear foot. I know of nothing that yields so much food per cubic foot as the Jerusalem artichoke. And we have several thousand square feet planted back in the Elfwood, where we have allowed it to go wild, which it does so easily–a permanent and easily maintained emergency food supply.
Anyone with slightly to very acidic soil and a cool climate can grow these. Where you want them to grow for food, just till the ground as the tubers will only grow large if the ground is friable. They spread from rhizomes and maintain themselves effortlessly. To maintain the patch, just leave half of them in the ground every year, or set aside one tuber for every eighteen inches you want to plant. Or you can leave them alone and just let them spread. Trust me, they will.