Why Do Voles Eat My Plant Roots?

Voles are small rodents that live underground and feed on vegetation. They are often confused with moles who feed on insects and invertebrates. Voles are vegetarian and will dine on the underground stems and roots of your plants when their usual forage is scarce during the winter. The damage to roots can kill smaller plants, but large vegetation such as trees can usually withstand vole nibbles. Voles will also chew on the bark of trees and eat into the surface seeking the nutritious cambium.

Tree roots are composed of hard tissue with the same vascular structure of which the main stem or trunk of a plant is comprised. The cambium is just under the surface of the root and carries nutrients and plant sugars up and down the tree. This means the cambium is rich in minerals and carbohydrates, making it attractive to the voles. When the season has become cold and herbaceous plants are scarce, the animal will forage on tree roots as a food source.

Voles eat 24 hours a day. They are out searching for food both day and night and primarily eat foliage, seeds, stems and bulbs. Underground vegetables are also at risk from vole feeding behavior. Voles will search for food in a 1/4 acre range, using old mole tunnels or their own surface runways. Voles live in burrows with a couple of adults and numerous young. When they feed, they cause plants to wilt, have stunted growth and sometimes even disappear as they pull them underground.

Voles only live two to 16 months. In that time they need to reproduce, which can be any time of the year but is generally in spring and summer. Females mature in 35 to 40 days and are capable of having multiple litters per year. Litters can result in three or more pups. Creeping voles may have four to eight litters of three to four babies each time. Townsend's vole is a less frequent breeder with only two litters per year but often four to seven pups. Gestation periods are less than a month and the female can be ready to breed again almost immediately.

You can find several types of mechanical traps to kill voles. The most common is the snap trap, which you bait with peanut butter or another tasty food. Voles will move around more in areas with weeds and grasses as cover from their predators. They are unlikely to run across a clear area, so mowing high vegetation will help control their movements. Tree barriers at the base of trees will prevent the rodents from feeding on the bark. Professionals use gases and rodenticides, but these are not registered for use by homeowners.