Voles are compact, short-tailed rodents that commonly infest yards and gardens, posing a threat to ornamental plants and root systems. Often mistaken for field mice, these pests cause damage by feeding on plant material both above and below the soil surface, resulting in landscape loss. Addressing an infestation requires a strategy that begins with accurate identification, moves to environmental modification, and concludes with active removal.
Confirming the Pest and Damage
Accurately identifying the pest is essential, as voles, moles, and gophers require different control methods. Vole activity is characterized by a network of shallow, well-defined surface runways, typically one to two inches wide, clipped through the grass and ground cover. These pathways connect small, open entry holes, often about the size of a golf ball. These holes lack the large, excavated soil mounds left by gophers or the raised, ridged tunnels created by moles.
The visible damage to plants is a strong diagnostic indicator, particularly the girdling of trees and shrubs near the soil line. This damage occurs when voles gnaw away bark, severing the plant’s ability to transport nutrients and water, which can kill young woody plants. The gnaw marks are irregular and occur in patches, typically measuring about one-eighth inch wide, distinguishing them from the larger marks left by rabbits. For perennial plants, wilting or yellowing foliage indicates underground feeding, suggesting that the roots or bulbs have been consumed.
Modifying the Environment for Deterrence
Long-term management involves making the environment inhospitable by removing the protective cover voles require to evade predators. Voles thrive in areas with dense vegetation, which provides both shelter and a food source. Regular lawn maintenance is the first line of defense; keeping grass mowed short and removing weeds and plant debris limits their travel and foraging security.
Thick mulch is a major draw, providing an insulated, dark, and moist environment for burrows. Maintain a thin mulch layer, or create a buffer zone of bare soil or coarse gravel around the base of trees and shrubs. Gravel is an effective barrier because voles are reluctant to tunnel through the sharp material. Removing supplemental food sources, such as fallen birdseed or unharvested root vegetables, also reduces the area’s attractiveness.
For vulnerable plants and young trees, physical exclusion provides reliable protection against feeding. Construct a protective guard from quarter-inch galvanized hardware cloth around the base of the trunk. This cylinder must be buried six to twelve inches deep to prevent tunneling beneath it and extend high enough above the ground to protect the bark above the snow line. Garden beds can be protected by burying a hardware cloth fence six to ten inches deep around the perimeter, with the mesh extending at least a foot above the soil.
Direct Intervention and Removal Tactics
When environmental modifications are insufficient, direct intervention through trapping or repellents is necessary. Trapping is effective for reducing small populations and involves placing mouse-sized snap traps directly into active runways. Traps should be placed perpendicular to the path of travel, ensuring the trigger rests squarely in the center of the runway, and should be anchored to prevent movement.
Effective baits include peanut butter mixed with oatmeal, or small slices of apple, as voles are herbivores. Wear gloves when handling and setting traps to avoid leaving human scent that can deter the rodents. Deploy a high number of traps simultaneously across all active runways to maximize success, since voles reproduce rapidly. Repellents offer a non-lethal alternative, relying on foul-tasting or foul-smelling ingredients such as castor oil, dried blood, or capsaicin to make plants and soil unpalatable. These products must be reapplied frequently, especially after rainfall, to maintain efficacy.
Chemical rodenticides are a final option, but their use carries significant risks and must be approached with caution, prioritizing the safety of non-target animals. Rodenticides pose a primary risk to pets or wildlife that consume the bait directly, and a secondary risk to predators like owls or coyotes that feed on a poisoned vole. To mitigate this danger, all toxic baits must be secured inside tamper-resistant bait stations that are clearly labeled and placed strictly according to the product’s Environmental Protection Agency (EPA) approved label. Using a toxicant for a species not explicitly listed on the label, or failing to follow all placement instructions, is a violation of federal law and can lead to accidental poisoning.