Food shortages in winter force animals to feed on bark, twigs, flower buds, and foliage. Deer, rabbits, mice, and voles are the usual culprits. Using tree guards or 1/4-inch mesh hardware cloth can protect tree trunks. The cylinder should extend 2 to 3 inches below the ground line for mice and 18 to 24 inches above the anticipated snow line for rabbits. For deer, a fence at least 8-feet high or utility netting wrapped around the head of the tree is the best defense.
Animal repellents can also be applied to trees, shrubs, and evergreens to help keep these animals from making a feast out of your investment. Repellents will work better in drier months for they will eventually wear off with wet weather and need to be re-applied. It is best to start using them before the snow starts to fall and re-apply every month, or so, to keep the animals away.