Voles, also called meadow mice and meadow voles, are small, stocky rodents, measuring about seven inches long at maturity. Adults are chestnut brown in color, mixed with black on the back; their underparts are dark grey, and their feet are brown. Voles are mostly vegetarian, feeding on a variety of grasses, herbaceous plants, bulbs and tubers. They can damage trees and shrubs in the fall and winter when they gnaw off tender bark and roots, if this gnawing girdles the tree, it will die.
The voles live in small colonies of a few to many. They live mainly in grass meadows where they build distinctive runways which crisscross the area. Often gross cuttings can be found in these runways. They also dig underground burrows where they construct food and nesting chambers. Voles do not hibernate and are active throughout the winter.
During the winter in snow covered areas such as ours, the voles make runways beneath the snow and feed on the snow flattened grasses. They also burrow up through the snow to reach gross seed heads. Immediately after the snow melts, their runways often become visible on the ground. Other garden damage that occurs under snow cover often escapes notice until it is too late.
Voles cause damage by feeding on a wide range of garden plants. Do not confuse vole damage with damage by rabbits, which includes stems clipped at a smooth 45-degree angle and wider gnaw marks. Stems browsed by deer usually have a rough jagged edge. Voles damage to trees and shrubs is characterized by girdling and patches of irregular patterns of gnaw marks about 1/16 to 1/8 inch wide. Gnawed stems may have a pointed tip.
Control Methods: Damage to lawns can be reduced by mowing close in the fall before snow arrives. Also, remove all tall grassy cover near lawns. To repair damage to lawns from runway construction, rake, fertilize and water affected area.
Wire Fencing - Encircle young trees and shrubs with 1/4-inch wire mesh or 3-inch diameter Vexar plastic mesh cylinders. This barrier should be placed 18 inches above the ground and 3 to 6 inches below the surface.
Trapping - Use mouse traps to remove small populations of voles. Place traps perpendicular to runways with the trigger end in the runway and bait with small amounts of rolled oats and peanut butter. Set traps in the fall before most of the damage occurs.
Fumigants - The method of using gas cylinders or smoke does not usually work because voles’ burrows are too shallow and complex.
Repellents - Repellent systemic tablets seems to work well for vole protection. These tablets are put just above the root base of the tree, shrub or plant. The bitter taste is taken up by the plant, making roots, stems and foliage bitter. These tablets need to be applied every two years into the soil.
There are several other commercial repellents available for protecting plants from voles. They must be applied before damage occurs. Voles usually damage plants at or just beneath the soil surface, making adequate coverage difficult. Because repellents may be washed off by rain, sprinklers or even heavy dew, you must reapply them for continued protection. Do not apply repellents to food crops unless such use is specified on the label.