Voles are small, stout rodents that pose a serious threat to gardens and landscapes by consuming plant material both above and below the ground. A key sign of a vole infestation is the presence of surface runway systems, which are well-worn paths through the grass or mulch. Damage also manifests as the girdling of trees and shrubs, where voles chew the bark and cambium layer near the base. The disappearance of bulbs and roots causes plants to suddenly wilt or fail to emerge in the spring. Recognizing this specific pattern of damage, particularly the irregular gnaw marks left on bark, confirms that a vole is the target pest.
Blocking Access with Physical Barriers
Physical exclusion offers a reliable, long-term solution for preventing voles from accessing vulnerable plants. This involves installing barriers made from hardware cloth, a fine, galvanized wire mesh that voles cannot chew through or squeeze past. To be effective, the mesh size must be one-quarter inch or smaller, as larger mesh allows the rodents to pass.
Individual trees and shrubs can be protected by creating a cylindrical barrier around the trunk. This cylinder should be buried six to twelve inches below the soil surface to deter burrowing. It must also extend at least twelve to eighteen inches above the ground line to safeguard against damage during winter months when snow cover allows voles to reach higher bark.
For protecting entire garden beds, the hardware cloth should be installed as a perimeter fence with a horizontal L-shaped extension buried beneath the soil. This involves digging a trench and bending the bottom six inches of the mesh outward at a ninety-degree angle before backfilling. This buried flange prevents voles from tunneling vertically beneath the barrier to reach the protected area.
Making the Environment Unsuitable
Modifying the landscape to eliminate the cover and food sources voles depend on can reduce their population and activity. Voles prefer areas with dense overhead protection because it shields them from predators such as hawks, owls, and foxes. Removing these sheltered habitats forces the voles into the open, making the area less appealing for foraging and nesting.
Managing organic debris and mulch is a primary step, as voles use these for insulation and cover. Mulch layers around trees and garden beds should be reduced to a depth of no more than three inches to minimize suitable habitat. Additionally, maintain a bare soil buffer ten to twelve inches wide around the base of vulnerable trees or garden borders.
Keeping lawns mowed short also reduces available cover and is effective against meadow voles, which create surface runways in dense grass. Regularly cutting grass to a height of about one-and-a-half to three inches exposes the voles to predators and discourages runway establishment. Storing woodpiles, brush, and other debris away from cultivated areas eliminates nesting sites, pressuring voles to relocate.
Using Scent and Taste Deterrents
Repellents work by introducing a taste or scent that voles find unpleasant, persuading them to seek food elsewhere. Commercial granular repellents utilize active ingredients like castor oil, which contaminates the soil and makes the voles’ food sources unpalatable. Liquid sprays contain compounds such as capsaicin, derived from chili peppers, or Thiram, which coat the plant material.
These deterrents are applied directly to the bark of trees and shrubs to prevent winter girdling damage. Voles avoid the treated plants due to the noxious flavor or the irritating sensation caused by the chemicals. Because these products are surface applications, their effectiveness is limited by weather conditions and requires reapplication after heavy rainfall, irrigation, or new growth.
While do-it-yourself mixtures may offer a temporary solution, professional-grade repellents are engineered for increased longevity and greater concentration. Deterrents are most effective when used as a complement to other control methods, helping to steer voles away after habitat manipulation has made the environment less welcoming.
Direct Removal Through Trapping
When prevention and deterrence are insufficient, direct removal through trapping can quickly reduce the number of voles. The most practical method involves using common mouse-sized snap traps, which are appropriately sized for the rodents. These traps should be placed directly within the established surface runways where the voles travel.
For maximum effectiveness, the snap trap must be positioned perpendicular to the runway, ensuring the trigger plate sits directly in the vole’s path. While voles may trigger the traps simply by moving along their route, baiting significantly increases the success rate. Effective baits include apple slices, a mixture of peanut butter and oatmeal, or a small piece of carrot.
Because voles are prolific breeders, setting a sufficient number of traps is important, often meaning ten to twenty traps in a localized problem area. To ensure the safety of pets, children, and non-target wildlife, all set traps should be covered with an inverted box, lumber, or a paint can with a small opening. The traps should be checked twice daily, and the process must be persistent, continuing until no new voles are caught for several days.