If deer are frequent visitors in your yard, and you also have a recently planted tree, it’s important to protect your tree from mid-August through April with hardware cloth, welded wire or a plastic tree guard.
Deer can damage young, tender trees by rubbing their antlers on the thin-barked stems of deciduous trees. The resulting damage—a shredded tree trunk—kills the living tissue under the bark. It then becomes more difficult for the tree to move water and nutrients, making it susceptible to decay and decline.
Prevent damage to the stem by placing a protective, light-colored plastic tree guard around it or by fencing it off completely with welded wire or hardware cloth. If you choose the welded wire fence, be sure to use hardware cloth around the base of the tree as well to protect the stem from rodent damage in the winter.
Once the tree guard is on, make sure it fits all the way around the tree and will be tall enough to protect the bark from a rutting deer. If you choose a tree guard, be sure to remove it in the spring in order to discourage borers and allow the tree trunk to capture light and photosynthesize. Welded wire fence and hardware cloth may be left on all year, but check it in the spring to ensure the tree hasn’t outgrown it. If you forget to check it, and the tree outgrows the stem protection, the wire can girdle and kill the tree—which is just the opposite of protecting it!
For more information visit: http://www.myminnesotawoods.umn.edu/2009/12/tree-stem-protection/