Use 1/4-inch hardware cloth or plastic cylinders to protect individual trees and shrubs by wrapping the base of the trunk up to about 18 inches high.
The cylinder should be tight to the ground or buried slightly and should extend higher than the maximum depth of snow in winter, including drifts. The height of the cylinder should be at least 18 inches above the snow depth, if possible, where rabbits are also a potential problem. When making the cylinder, overlap the edges at least 1 inch, and fasten them securely so gaps do not form that could admit voles. Cylinders of galvanized hardware cloth should last about five years, so make them large enough in diameter to accommodate expected trunk growth if they remain in place during the growing season. Remove and replace cylinders promptly if the trunk becomes constricted, and do not allow outside materials (leaves, mulch, grass clippings) to accumulate in the cylinders.
Clear and/or mow grass and weeds in the orchard and around each tree to reduce cover for the voles during the winter.
