Or; How to Build a Garden on a Rock Pile Without Digging All The Rocks Up
Use cardboard. I think this might be a bastardization of the Lasagne Method of gardening.
Several weeks before you want to plant, pick a grassy spot for a bed and cover it with large sheets of cardboard. Large boxes from furniture and appliance stores work best but anything will do. Cover the cardboard with straw or something to hold it in place. A few large rocks or some pallets will also do. Water the cardboard if the weather is dry. The water helps the cardboard start to break down. With just a tad of luck, the grass will die about the time the cardboard starts to loose some of its integrity.
You can then cover with enough potting soil or dirt or mulch to grow shallow root crops or you can cut holes in the cardboard for each plant. Mulch well, fertilize and water.
In my garden I used this method in a few places where I wanted to plant but mostly I used it in the walkways and up the sides of the raised beds. This sure does cut down on weeding.
Use it up, make it do or do without!