Voles are small, stout-bodied rodents often mistaken for common house mice or moles due to their size and subterranean activity. Sometimes referred to as meadow mice or field mice, voles possess a blunter nose, shorter tail, and smaller eyes and ears compared to a typical mouse. They are primarily herbivores, and they do eat roots and tubers, especially when other food sources are scarce. Voles cause significant damage to gardens and landscaping because they do not hibernate and remain active year-round, feeding beneath the protective cover of snow or dense vegetation.
Primary Food Sources and Damage Types
Voles are opportunistic herbivores whose diet shifts seasonally based on availability, though plant matter remains their primary sustenance. During warmer months, they mainly consume the stems and blades of grasses, herbaceous plants, and seeds. They create extensive networks of surface runways in the turf as they travel and clip vegetation.
The most destructive feeding occurs when voles focus on subsurface plant parts, including roots, bulbs, and tubers. They actively seek out and consume the underground storage organs of plants like tulips, lilies, potatoes, and carrots. This feeding often causes plants to wilt suddenly or collapse entirely because the root system anchoring and nourishing the plant has been severed.
When green forage becomes scarce in the fall and winter, voles turn to the bark and roots of trees and shrubs. They feed on the bark near the soil line, or several inches up the trunk under the cover of snow. This gnawing can completely remove the bark in a ring around the trunk, a process known as girdling. Girdling disrupts the flow of water and nutrients, which can kill young or thin-barked trees and shrubs.
Distinguishing Vole Activity from Other Garden Pests
Confirming vole activity requires observing specific evidence that differentiates their damage from other common garden pests. The most characteristic sign of a vole infestation is the presence of well-defined, crisscrossing surface runways in the grass. These trails are about one to two inches wide and are created by voles repeatedly traveling and clipping vegetation along the same path.
Voles also construct shallow burrows, but unlike moles, their entrances are small, clean, round holes typically about 1.5 inches in diameter. These openings are often hidden beneath dense vegetation, mulch, or snow cover and connect directly to the surface runways. Moles are insectivores and do not eat plants; their presence is characterized by deep, raised ridges and large conical mounds of soil pushed to the surface.
When voles feed on woody plants, they leave distinct gnawing marks on the bark or exposed roots. These marks are irregular and ragged, typically measuring about one-eighth of an inch wide and three-eighths of an inch long. Gophers create fan-shaped mounds as they push dirt from their deeper tunnels. Damage to roots caused by gophers tends to be centralized beneath the mound, unlike the scattered, shallow feeding of voles.
Effective Methods for Vole Control
Controlling vole populations involves exclusion techniques and habitat modification to make the area less appealing for feeding and shelter. Since voles rely on dense cover for protection from predators, removing heavy mulch layers, keeping grass mowed to three to six inches, and eliminating weeds creates a less secure environment. Clearing a vegetation-free buffer zone of at least four feet around valuable trees and shrubs also discourages voles from approaching.
Exclusion is an effective method for protecting individual plants from subsurface root and bark damage. Young trees can be protected by installing hardware cloth cylinders around the base of the trunk. Ensure the barrier extends at least six to ten inches below the soil line and is tall enough to reach above the anticipated snow line. For bulbs or susceptible plants, planting them within underground wire cages offers a barrier against feeding.
When direct control is necessary, trapping can be effective for managing smaller populations. Mouse-sized snap traps, baited with peanut butter, apple slices, or oatmeal, should be placed perpendicular to the active surface runways. Traps must be covered with a small box or bucket to shield them from non-target wildlife and pets, and they should be checked frequently. While rodenticides are available, their use requires caution, as the bait poses a risk to non-target animals, including pets and predators that consume poisoned voles.