That was (and still is) my stumbling block, too. I'd love to do mine in stone, but I can't even get a wheelbarrow in there until July because it's too wet. I know I'd have to add rock on a regular basis, as the dug-out areas refill with sediment each year. It's just too hot for me to think about moving rock in during the middle of summer. I've got the area all hemmed-in with plants too, so there's no getting a vehicle down there.