Here is an example of using a row cover to protect plants from insects, birds, and extreme sun. Note that fine, light fabric mesh is supported by 1/2 inch wide pvc piping. The mesh is "weighted" down on top by a few pieces of mulch and by bricks or stones or stakes on the sides so you can access the plants to weed or harvest. Since these are low crops the posts are stuck in the ground. For tallerer crops like blueberries, one could pound short, wide pvc piping posts in ground then place 1/2 inch pvc piping inside these short posts. Water, air and sun pass through these fabric covers. One online source to purchase translucent polypropylene fabric is through Gardens Alive