Getting ready to plant some grass for a customer. New ground just got cleared of predominantly chestnut oaks. It is full of rock, like 5 acres of driveway full of rock. Most are golf ball size or smaller a few baseball size or so. I know grass will help hold them down if I can get it growing. The land is poor so fertility is first and organic material is non existent. I know some of you guys live in some rocky spots. How is the best way to smooth it up and seed it? Thanks for any help you can give.