In addition to materials laid directly upon the ground or the plants, there are types of winter covering that involve building a shelter of burlap or similar material about the plants and wrapping the aboveground parts in hay, straw, paper and other protective materials.
Evergreens, even kinds considered fairly hardy, are much more susceptible to winter injury than are leaf losing (deciduous) trees and shrubs. They transpire moisture through the leaves in winter as well as in summer, and protection from high winds and bright sunshine may be very necessary in cold regions, especially for those evergreens that are not natives. Burlap, neatly nailed to 2 by 4 in. supports on the exposed sides of the plants, is helpful. A few branches of Pines or other evergreens stuck in the soil so that they give protective shade may be all that is needed for some of the smaller, growing evergreens liable to winter damage.
Deciduous trees and shrubs, the tops of which are somewhat tender, as are, for example, Fig trees in the vicinity of New York City, and Hydrangea macrophylla rather farther north, may be successfully brought through the winter by tying their upper parts together, wrapping them in a thick layer of straw, hay, newspaper, old blankets or other material that provides good insulation, and encasing the whole in a layer of waterproof building paper. This is done before very hard frost, and the covering is removed in spring after danger of severe frost has passed.