The greatest danger winter poses for plants is prolonged freezing of the rootball. During colder months, keep potted plants particularly at risk of frostbite nestled against a wall close to the house, clustered together. This should help keep them warm. Protect the container in any number of ways: wrap it in burlap or bubble-wrap, place the pot on top of a thick sheet of styrofoam or apply an over-pot of coconut fiber. The top layer of soil can be insulated using leaves, evergreen branches or coconut matting. If your area experiences subfreezing temperatures, the exposed part of the plant should also be covered with burlap, agricultural fabric, jute wrappings or reed matting. Water plants occasionally as long as temperatures are above freezing, and shade evergreens from late-winter sun.