Prepare for Voles - Reducing Winter Damage

Voles can do considerable damage to landscape plants in the late fall and winter. The following is information on voles and how to reduce winter damage in landscapes.

Pine voles live primarily in shallow underground tunnels, but will sometimes forage aboveground. In addition to the damage done during winter, pine voles may cause damage throughout the growing season. Pine voles eat bulbs, tubers, seeds and bark (root bark included), but can damage a wide variety of other plants, including roses, fruit trees, flowers and vegetable garden plants. In many cases the damage from pine voles goes unnoticed until the owner discovers the decline or death of a particular plant. In vegetable gardens, entire plants may be pulled partially or entirely underground. Wilted plants with chewed roots are commonly observed. In flower and bulb gardens, plants may fail to grow in the spring after underground tubers, roots and bulbs have been consumed by pine voles.

Meadow voles prefer wetter soils than pine voles. They live primarily above ground, making shallow surface tunnels or runways. Meadow voles gnaw bark from trunk and branches of trees and shrubs during the winter and early spring. Deep snow cover allows for vole damage to extend higher on trees and shrubs. They also chew out crowns of herbaceous perennials and grasses, and chew out trails in the turf. These trails can be seen in turf or snow cover. Nests are made of interwoven strands of dry grass and contain caches of food. Unless the damage is severe, perennials and grasses will generally recover. As mentioned above under rabbit damage, the survival of woody stems partially girdled depends upon the extent of the damage. Often, deciduous shrubs will send up new shoots later in spring.

Keep grass and ground covers away from trunks of trees and shrubs. Voles require vegetation or other cover in order to survive. By eliminating or reducing this cover one reduces their preferred foods, exposes them to predators and exposes the animals to severe weather. In the home landscape, avoid deep mulching in gardens and plant beds where voles are known to be a problem. Certain mulches are more likely to attract voles than others; avoid using mulches with fine or small particle sizes. Large-sized crushed-stone mulch and pine bark mulch may reduce vole tunneling. Plastic and landscape fabric mulches may increase vole populations and subsequent damage. Frequent mowing of grass around trees and shrubs will help to reduce the potential for vole injury.

Reprinted from the March 19, 2004 edition of Landscape Alert Newsletter from Michigan State University.

Landscape and Turf - Vole Damage

Vole damage can be very extensive in landscapes and often is seen in the fall and winter on woody plants. The following is an article on voles and their control.

Description

The meadow vole, also called meadow or field mouse, is a common problem many landscapes in Delaware. These pests can be very destructive to ornamental plantings, including annual and perennial flowers, turf, shrubs and small trees. Voles are compact animals with stocky bodies, short legs and short tails. Their eyes are small and their ears are partially hidden. The underfur is generally dense and covered with thicker, longer guard hairs. Typically, voles are brown or gray, though many color variations exist.

Voles are active day and night year-round. They construct extensive tunnel systems and surface runways. Several adults and young may live in one tunnel system. Populations seem to peak every 2 to 3 years, depending on food availability, climate and other stress factors.

Damage

Voles damage plant materials by their feeding habits and their tunnel systems, which can ruin turf as well as interfere with irrigation water patterns. Voles will girdle fruit and forest trees causing commercial damage. They also cause damage to ornamental plants. Their teeth marks are very haphazard leaving no particular pattern on the bark or inner portion of the plant material. Voles will feed on trees year-round with most of their damage occurring in fall and winter. In late summer and fall, they will store seeds, tubers, bulbs and rhizomes for winter feeding.

An extensive surface runway system is the most easily identifiable sign of voles. Vegetation near well-traveled runways may be clipped close to the ground. Feces and vegetation may be found in the runways. Pine voles, also native to Delaware, differ from the meadow vole in that they rely exclusively on a system of underground tunnels.

Control

The best way to control voles is to take their cover away. Voles like vegetative covers or litter piles, because they provide food and cover. Elimination of these areas can help reduce populations. Keep weeds or dense brush away from shrubs and tress. Rake and clean up dead vegetation from areas where runways are seen.

Mechanical: Tree guards of hardware, cloth or other suitable material can be used as a barrier around young trees. Since voles are excellent diggers, place the bottom of the guard 6 inches below the soil surface.

Trapping: Use of snap-type mouse traps may be effective in eliminating small populations or reducing their numbers to reduce their damage. Traps should be placed with the bait side in the runway. Baits of peanut butter and oatmeal or apple slices may be effective. Live traps may also be employed.

Poison Baits: Pelleted commercial baits are effective when placed in the runways or burrow openings. Anticoagulant baits are also effective, though multiple feedings are required for control. Repellents are not usually effective. Such baits should be used only by commercial orchards or nurseries. Other than broadcast and hand placements, baits can be placed in various types of waterproof paper tubes. The tubes should be 5 inches long by 1.5 inches in diameter with the bait glued inside the tube.

Adapted from the Delaware Cooperative Extension Factsheet HYG-62 by Dewey M. Caron, Extension Entomologist