I put out a request for ideas for articles amongst the other garden editors. And one of the main animal complaints they had was from voles. Since voles are so little known among people, they are frequently confused with moles. While they both can have extensive burrow systems, voles are very different from moles. First, voles are vegetarians and moles are not. Voles will attack the roots of plants, moles will eat the worms and grubs. Second, voles are rodents, while moles are not. Third, voles are about half the size of a mole or in other words about the size of a common house mouse.
Since voles do not hibernate, they can damage orchards and ornamentals year around with their gnawing on the bark. You can identify vole damage by the gnaw marks which are about 1/8 of an inch wide and 3/8 inch long and about 1/16 of an inch deep. Rabbit gnaw marks, I am told, are larger and lack the distinct tooth marks. Another sign of voles is the extensive surface runway system with accompanying burrows. In areas of heavy vole activity, you will actually see trails in the grass, where their activity has beaten the grass down to the soil. The pine vole, however, does not typically use surface tunnels so always keep that distinction in mine. By contrast, moles rarely come to the surface.
One of the best ways to protect your plants from vole damage is by modifying the habitat. Keep your grass trimmed short and reduce ground cover. The more exposed the voles are to the sky, the easier it will be for predators to maintain low vole populations. You also should eliminate bird feeders that spill food on to the ground.
You can protect your young ornamentals from vole damage by burying 1/4 inch weave hardware cloth at least 6 inches below the ground surrounding the plant. Then extend the mesh cylinder at least 6 inches above the ground around the plant. I would think that the plant's trunk could also be wrapped to protect from surface chewing.
Next month we'll talk about how to control them with trapping and toxicants.
