Those living in regions where snow reigns supreme, gardeners need to plant cold-hardy trees, shrubs, and perennials if they want them alive to see the following spring. But for those of us residing where the winters are milder, protection from hard frosts can make all the difference in keeping generally non-cold hardy plants such as fuchsia, bougainvillea, succulents, or citrus alive.
There are a number of things you can do to protect plants from frost. The first thing is to move any plants that you can underneath the eaves of your home. If they can't be moved they can be covered with cloth tarps, newspaper, burlap, or cardboard. In fact, cardboard boxes make excellent night time plant covers. Old drapes are also perfect to repurpose as plant protectors. Young trees and citrus can be protected by wrapping their trunks with burlap.
Some gardeners use plastic and it works well. The key with using plastic for frost protection is not to let the plastic touch the plant in any way. So, stakes or bamboo can be pushed into the soil parameter to hold the plastic away from the plant.
If the temperatures rise significantly in the day time hours, the plant covers should be removed and placed back on at night. Most gardeners recommend removing any type of protection in the day if it's touching the plant.
Another technique which works surprisingly well, but is more expensive than the ideas is to spray antitranspirant it all over the plant. Antitranspirant slows down the leaves transpiration by protects plants by coating the foliage and holding in the moisture. This product is often sprayed on Christmas trees to keep them fresh.
Antitranspirant lasts about three months, so gardeners who use it usually spray their plants a couple of times during the winter. This technique works best where the winters are mild, but frosty.