Mice, rabbits, voles and deer can all cause severe damage to plants in the winter by feeding on twigs, bark, leaves and stems. They can eat shrubs to the ground and also girdle trees and shrubs by chewing through the bark.
The best overall strategy for protecting your trees and shrubs from animal browsing is to reduce areas of habitat and use physical barriers to prevent them from getting to your plants.
Reducing animal damage on plants starts with eliminating protective cover and a desirable nesting environment.
Cut grasses and other vegetation short in late fall within 2 feet of young trees to reduce protective cover for mice and voles that might feed on trunks and stems.
Discourage rabbits from taking up residence in your yard by reducing protective cover, removing brush piles, and fencing off other hiding places such under decks and other structures.
Protect tree trunks with cylinders of ¼-inch mesh hardware cloth around the trunk of the tree about 6 inches away from the trunk. This can be kept on year-round.
For mice, the cylinder should extend 2 to 3 inches below the ground line.
For rabbits, the cylinder should extend 18 to 24 inches above the anticipated snow line.
Make sure there are no gaps between the bottom of the mesh cylinder and the ground where animals could crawl under the fencing. For small trees, plastic tree guards are also effective.
Protect shrubs from rabbits by fencing the beds with hardware cloth.
Enclose the lower branches as well as the trunk.
Check fenced areas frequently to make sure rabbits aren’t trapped inside.
If you have many trees or shrubs to protect, using screens and wraps may be too expensive and time consuming. In such situations, repellents may be the best solution. A repellent is not a poison, it simply makes plants taste or smell bad to animals. Spray or paint repellents on trees and shrubs.
One application of a repellent is usually enough for the entire dormant season.
Deer feed on terminal and side branches of small trees and shrubs. They may rub their antlers and foreheads on tree trunks in late summer and early fall to remove the velvet covering from their new antlers (called deer rub). This can damage tree bark going into winter months.
The Minnesota Department of Natural Resources considers deer a protected game species. Therefore, the best strategy is to remove habitat options and erect physical barriers. If deer are starving, there is little that will prevent them from feeding on your plants as hunger will overcome a bad taste or fear.
Manage deer by excluding them with fencing. Fences should be 8 feet high and well-constructed to prevent deer from breaking down the fencing or jumping over it. When motivated and provided enough space to get a running start, deer can clear fences as high as 12 feet.
Electric fencing such as that used for cattle may also provide some protection from deer.
Various repellents exist on the market in liquid, granular or powder forms. Most need reapplication after rain or irrigation.
