The well over a foot of snow we were shellacked with in February is now a distant memory for most of us. The annual appearance of the Easter bunny is right around the corner. Alas, his relatives were having fun chewing on our landscape shrubs and small fruits during the past February snow event.
Another rodent having fun feeding during February was meadow mice, also known as meadow voles. Heavy and consistent snow cover was the perfect recipe for chewing damage by these rodents.
Now that the weather has warmed, gardeners are once again outdoors cleaning their landscape beds and finding the damage left behind by the rodents. Protected by snow cover, the meadow mice gnawed off the outer bark of our shrubs such as viburnums and small fruits such as raspberries in search of the tender green cambium just beneath. The cambium is the area just under the bark that contains the vascular tissue of plants. Likewise, rabbits used the snow cover as a natural ladder for climbing into the crown of shrubs while chewing on the bark and cambium.
Now is the time to check underneath the canopy of our landscape shrubs and small fruits and look for chewing damage of the cambium on smaller twigs and branches. Chewing damage will appear white on the bark instead of dark gray. If the chewing damage completely encircles the twig or branch, the top portion is history and will begin to die back in early summer.
Mouse damage essentially has the same result, but the girdling typically will be found much lower on the trunk. Mice normally have a much greater range of plants they will chew on. Damage is often more irregular, not girdling the whole way around, giving the plant at least a fighting chance to survive. Unfortunately, this is not the case for fruit trees and small fruit crops. These can be completely girdled at ground level where mice have over-wintered. Mice can also chew into the upper canopy of twigs such as in the case of a dense juniper covered by snow. The branches become a superhighway for their movements, and the snow cover protects them from predators such as hawks.
Your best defense here is a good offense, so go ahead and get the pruning equipment out and sharpen the blades. On most shrubs, you can cut off the twigs just beneath the girdled portion and the plant will sprout back new shoots all along the stems that are left. If you leave a few long stems that were not fed upon, the plant is likely to look lopsided come next summer. You can expect a mature and healthy shrub or small fruit to regrow quickly back into what it was in about two or three seasons.
To prevent rodent problems next winter, chicken wire (a fine mesh) can be your best friend when it comes to keeping hungry varmints away from valuable specimens. You may only need to encircle the trunk of a tree to about two feet, or you can make a cage to encircle a shrub or fruit crops.
If you live in the country, be observant of natural predators in the area such as hawks, owls and fox. If you can create a perch for predacious birds, such as leaving a dead tree standing, you will invite them to patrol your area. It is surprising how one nice hawk family can keep a rodent population from exploding.
Another idea is to do nothing; some gardeners allow the chewing as nature’s way of natural pruning.
Editor’s note: Portions of this article was used with permission from Rebecca Finneran, Michigan State University Extension Knox County.