I have 4 acres of heavy clay soil that is hard to grow anything in. I have been hauling in bags of leaves every fall from anyone who will let me have them. I have added lots of grass clippings and all my kitchen scraps go into the same pile. I have planted potatoes in this leaf/compost pile for three years now and get amazing results. I rarely water them and in the fall I just paw around in there and am able to harvest nearly all the potatoes with my bare hands....no digging. This season I spread woodchips on top of it all. I plan to add more leaves again too. Oh, and a layer or two of cardboard. Will see how this works out.