An unheated PVC hoophouse can be a useful addition to your garden. It keeps excessive rain off the plants, blocks the wind, raises daytime temperatures 5-10 degrees (and often much more), and keeps frosts and heavy dew off the leaves. This can extend your warm-season gardening a month or more at both ends, and makes it possible for year-round gardeners to grow a wider variety of plants through the winter.
PVC hoophouses are inexpensive to build, and can be put up in about an hour. Take a look, and decide for yourself!