I have been using spun-bonded row covers for years on my fall garden. They keep greens and root crops fresh deep into the winter, even under snow. This year I decided to suspend them on hoops rather than lay them directly on the greens, for better air circulation. I made two kinds of hoops: plastic and wire. In this video you can see how I made the hoop houses or low tunnels for the row covers. The plastic tubing hoops are sturdier, but they are more expensive to make than the wire hoops.