I have two customers that have newer (< 5 years old) homes where the contractor planted grass. They both have a great deal of rocks ranging from pebbles on the surface to ~5"x5". I have thought of two approaches: - Rent a skidsteer, get a couple yards of screened topsoil, put 1 or 2 inches down all over the lawn, seed it, and see how that goes. - Slit seed it twice, at 90 degree angles. My main qualm with the skidsteer/topsoil method is the fact that the lawns are already meeting the sidewalk at the appropriate level. I know, I know, question and it's kind of without pictures, but do you have any suggestions?