By Gary Wyatt
Natural resource management educator
U of M Extension Service
Have you ever noticed animal damage to trees or other plants during spring yard work? Animal damage during winter months can be devastating, stunting growth severely or even killing the plant.
Proactive and preventive measures can be implemented to minimize and control animal damage. Rabbits, mice, voles and deer cause the most damage, gnawing the bark of trees and other plants during winter.
Wire mesh such as quarter-inch hardware cloth or a plastic drainpipe circling the trunk is commonly used. It should be two to three inches below the ground and 18 to 24 inches above the anticipated snowline. These structures need to be checked each year or removed during the growing season to prevent girdling the trunk as trees grow. Apple trees are especially prone to damage. Plant beds or perennial gardens can be fenced with chicken wire. Check fences frequently. If large numbers of plants need to be protected, repellents may need to be used. Deer can also cause damage to wintering landscapes. Fencing is usually expensive and not practical. Odor, taste and visual repellents can be used to repel many wildlife species but may have varied effectiveness. Human hair, soaps, garlic oil, and hot sauce can be applied to branches and foliage to discourage browsing. Weather, application frequency, animal population and feeding pressure affect the success of repellents. Some animals become acclimated to the repellent; therefore, alternating repellents may need to be used.
Bud-capping of white pine and other conifer tree leaders has been successful. A paper cone or balloon is used to cover the main leader. Use a 4- by 6-inch piece of white paper, wrap it in a cone shape around the terminal bud and staple with an office stapler. The bud should be a half inch below the top of the paper. When balloons are used, simply put the balloon over the top of the leader about 1 to 2 inches. Periodically check the paper and balloon bud caps, and be sure to remove them in the spring.
To learn more about these and other preventive measures to minimize animal damage to trees and plants in your landscape, visit Extension's forest resources website at http://fr.cfans.umn.edu/extension/urban_com/index.html