Preventing Rodent Damage
Voles and other rodents can damage fruit trees over the winter months, warned Maurice Ogutu, University of Illinois Extension horticulturist.
“There are steps you can take, however, to protect your fruit trees,” said Ogutu.
Voles, he pointed out, usually live in areas where there is abundant grass and sedges. During the winter months, when the grass and sedges are dead, voles tend to burrow underground to overwinter, but they have less food choices, forcing them to feed on trees.
“Voles can damage fruit trees by feeding on roots, twigs, and stems,” he said. “They tend to girdle tree trunks commonly within 30 inches above the ground by eating tender new bark and the cambium layer underneath. The girdled tree dies in the spring since there is no means for translocation of food from the shoots and no cambium layer for replenishment of vascular tissues.”
Ogutu recommended the following methods to protect fruit trees from voles and other rodents.
“Use hardware cloth of one-eighth to one-fourth-inch mesh folded to form a cylinder of four to eight inches in diameter around the tree trunk,” he said. “Encircle the trunk with the mesh up to 20 to 30 inches above the ground. Extend the mesh two to four inches into the ground to also protect the tree from rabbits.
“Use white, spiraling, plastic tubes around the trunks of young trees. Cover the trunk up to two inches below the ground and check the plastic every year to ensure that it does not interfere with trunk growth.”
Chemical repellents that are bitter and have an unpleasant taste to voles and other rodents can also be used. Apply these repellents in the fall when trunks and branches are dry and temperatures still above freezing.
“Use poison baits during the dormant season by placing them one to two--feet away from the trunk in a slightly hidden spot but accessible to rodents,” he said. “Read and follow label instructions when using poisons.
“Poisons may not be effective when habitat is still present as more rodents can still move into the same site, and poisons are also harmful to human beings and wildlife.”