Our run is 25 X 100 and it was down to dirt in less than two weeks with just 4 chickens. The first two weeks I had chickens, I thought they should stay in the pen that we built for quite a bit of money. However, the hens didn't agree and kept escaping - jumping off the roof of their coop to freedom - so they free range now and the pen is just for show. However, it had ivy and pachysandra along with a nice grassy area and while the girls pretty much destroyed the English Ivy and grass, the pachysandra was left untouched and actually looks pretty good. btw, the grass never grew back even though they spend very little time in the run - just enough time to get in and out of their house. So, despite what the book "Free Range Chicken Gardens" says, I don't believe that it is possible to grown anything in your run; my chickens have pretty much destroyed everything growing in my backyard. Thank goodness I like chickens more than plants and I have a nice front yard where they don't go.