The purpose of a winter mulch is not to protect the plant from freezing but rather to protect the plant from rapidly changing temperatures, especially in the late winter and early spring. A few warm days in late winter may cause an unmulched plant to break dormancy prematurely. Or the freeze-thaw cycles may cause frost heaving, which damages the crown of the plant. Usually we can count on snow cover to protect the plant from these problems, but not always.

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