By Randy Nelson and Adam Austing, UMN Extension
Voles are small brown rodents about the size and shape of a mouse. They have small ears and a short tail. Voles are common in yards and fields where they spend a lot of time eating grasses and roots and making trails. We usually observe their small surface tunnels winding through our lawn right after snow melt.
The grass in these areas is usually eaten to the soil line, leaving the crown of the grass plant intact and healthy. In time, new leaves will emerge from the crown and fill in the bare areas. If no new growth is noticed after the rest of the lawn is actively growing, the affected areas can be reseeded with a good lawn seed mixture.
Voles will always be present, but there are steps to take to help discourage them from taking up residence in your yard this fall. Continue to mow the lawn while it is actively growing. Avoid mowing the grass shorter than two inches as this may expose the crown of the grass plant to severe temperature extremes resulting in winter injury. Eliminate any weeds, wild grasses, or litter from around the yard so it does not provide food and cover.
Voles do not limit themselves to just being a lawn pest. They often feed on the outer part of the trees and woody shrubs. If severe, vole damage on plants can cut off the route energy and other important resources take, eventually leading to the plant’s death. Just like in grass, this damage is often hidden by snow cover. There is little you can do to help once damage is revealed beyond trying to prevent the plant from further damaged.
Large vole populations can most effectively be reduced using toxic baits. There are some available for home use. Bait should be placed inside bait stations to reduce the risk of non-target species ingesting the poison. When using bait stations check them several times a week and replace any bait that has been consumed. Be sure to read and follow all directions and precautions on the label. Bait stations should be used with extreme caution because they may pose a threat to children and pets.
If voles have damaged your lawn, just give it some time, it will likely fill in once the weather warms. Remember that voles are always present and most of the time it is not worth the effort to try and control them. More information on voles can be found at: http://www.z.umn.edu/voles