Crop or floating row covers are placed directly over newly planted plants or seeded rows being careful to leave enought slack to allow for growth. The row covers provide extra warmth, protects from light frosts and accelerates growth. It also protects plantings from flying insect damage. The fabric is loose enough to freely pass air and water so it does not require special ventilation or watering. The row cover fabric can be anchored down with a light sprinkling of soil along the edges. Since I live on a "Pile of Rocks" I have also use rocks. I use prefer to use "fabric staples" recycled from wire hangers to hold my fabric down. If you are interested I will post instructions on how to make the hangers.