Voles feed on lawns under good snow cover, so the damage shows only when the snow melts, mostly in late winter and early spring, according to University of Minnesota Extension. Grass usually recovers slowly. Woody plants girdled at the base can be killed. Protection has to be in place in autumn, before the snow.
Key takeaways
- Voles stay active in winter and feed under good snow cover, so the damage is usually discovered only after the melt, in late winter and early spring.
- Lawn runways look alarming but grass usually recovers slowly; the plants that may not come back are shrubs and young trees chewed around the base.
- Prevention happens in autumn: pull mulch and tall grass back from trunks and fit guards before the first snow, since nothing can be done once the snow is down.
- Extension suggests quarter-inch hardware cloth around trunks, set about 6 inches away and buried 2 to 3 inches, and says total prevention is impossible.
- Voles damage plants, not houses: if you find droppings or gnawing inside a building, the likelier cause is house mice.
What are voles, and why do they thrive under snow?
Voles are small, stout-bodied rodents that live in grass and mulch, not in houses. Good snow cover insulates them and hides them from predators, so they tunnel and feed on lawns and bark all winter. University of Minnesota Extension says the damage is mostly seen in late winter and early spring, after the melt.
A vole looks like a mouse with a shorter tail, a rounder face and a stockier body. It spends its life at ground level, in tunnels through grass and under mulch. In summer it stays hidden. In winter, deep snow gives it a roof, and it can move freely between a lawn, a flower bed and the base of a tree without being seen.
That is why the damage surprises people. In December the lawn looks fine under a white blanket, and in March a network of narrow trails appears across it. Nothing happened overnight; it was a winter of feeding that the snow had hidden.
The pattern fits the Twin Cities well. A winter with a long period of steady snow cover gives voles what they need, and the melt, which can come quickly, reveals everything at once. We do not state snowfall figures, since sources disagree, but any winter with reliable snow on the ground is a winter when voles can feed unseen.
What does vole damage look like in spring?
Look for narrow, winding runways through the grass, about as wide as a finger, sometimes with small holes at the ends, and for bark chewed from the base of shrubs and young trees. The damage is often patchy, close to mulch beds, tall grass and brush piles, where voles had cover.
On a lawn, the runways show up as trails of flattened or clipped grass, often matted and brownish at first. They are usually surface paths rather than raised ridges. Extension says the grass usually recovers slowly, so patience is part of the answer.
On woody plants, the signs are gnawing at the base of the trunk, just above the soil or just above where the snow lay. If the bark has been removed all the way around, the plant is girdled and the tree or shrub can be killed, because the bark carries water and nutrients between the roots and the crown. The table below separates what recovers from what does not.
If you are not sure it is voles, photograph the damage and describe it to the dispatcher. Other causes can look similar, including salt injury along a driveway and snow mold in turf.
| What you find | What it means | Usual outcome |
|---|---|---|
| Narrow runways across the lawn | Voles fed and traveled under snow | Grass usually recovers slowly; reseed bare patches if the surrounding grass does not fill in |
| Bark gnawed partly around a shrub or tree base | Voles fed at ground level | Plant may survive; protect it next autumn and watch for dieback |
| Bark removed all the way around the base | The plant is girdled | Woody plants can be killed; consult an arborist or nursery about replacement |
| Holes and tunnels in mulch beds | Voles used the mulch as cover | Rake out and thin the mulch, and keep it back from trunks |
| Droppings and gnawing inside the house | Likely house mice, not voles | See our guide to when mice come in and call about mouse control |
What can you do in autumn, before the snow?
Cut tall grass and weeds back from young trees and shrubs, pull mulch away from the trunk, remove brush and woodpiles, and fit guards of quarter-inch hardware cloth. Extension suggests setting the cylinder about 6 inches from the trunk and burying its bottom edge 2 to 3 inches. Do it before the first snow.
These steps come from University of Minnesota Extension guidance on vole damage, and they are all about taking away cover or putting a barrier in the way. They cost little, and they are the only measures that work in time, because once the snow is down you cannot see the problem.
Repellents are another option when many plants need protection, but Extension notes that their effectiveness and duration depend on the severity of the winter and the availability of other food. Traps can help in small areas: standard snap traps set along runways or near tunnels will catch some animals.
Extension is plain that total prevention is impossible. The goal is to limit the damage to bark and reduce the local population, not to remove voles from the neighborhood. Our service page on vole and field mouse control explains how a technician can help with trapping and with a plan for the yard.
- Cut grass and weeds short within about 2 feet of young trees in late fall
- Pull excess mulch and grass away from the base of trunks
- Wrap trunks in cylinders of quarter-inch hardware cloth, set about 6 inches from the trunk
- Bury the bottom edge 2 to 3 inches so voles cannot crawl under, and leave room for the trunk to grow
- Extend the guard above the expected snow line; Extension suggests fencing at least 4 feet tall where larger areas are protected
- Remove brush piles, tidy bird feeders and trim shrubs up off the ground
What should you do in spring when you find the damage?
Wait to see what recovers. Rake the lawn only once it begins to grow, because aggressive early raking stresses it, and reseed bare patches if the surrounding grass does not fill in. For shrubs and trees, watch for dieback through the season. Plan guards for the coming autumn so the same plants are not hit again.
The urge in April is to rake and reseed at once. Extension advises against aggressive raking before the lawn has started to recover, since stressed turf is slower to come back. Damaged areas usually recover once the surrounding grass grows into them, though bare patches may need seed.
For plants, leave them through the first growing season before deciding. A shrub with partial gnawing may leaf out and survive, and a tree with a ring of missing bark may fail later in the summer. A nursery or arborist is the right person to judge, and replacement is a gardening question more than a pest one.
Spring is also the right moment to check the whole yard for likely cover. Note where the runways were thickest, because that is where grass is tall, mulch is deep or a brush pile sits. Fix those spots by autumn.
A yard calendar for vole damage
The useful work for voles is seasonal and starts in late summer. Cut and tidy in autumn, install guards before snow, leave things alone while the snow lies, then inspect and repair after the melt. Each step has a time, and the order matters more than the effort.
Late summer to early autumn: look at the yard with a vole's eyes. Where is the grass tallest, where is the mulch deepest, where is the woodpile or the brush? Those are the spots that give cover. Start thinning them while the weather is still easy to work in.
Late autumn, before the first lasting snow: cut grass short near young trees, pull mulch back, and fit hardware cloth guards. Check that guards sit loose enough around the trunk and have no gap at the bottom. Put away bird feeders that spill seed, because seed feeds the animals you are trying to discourage.
Winter: there is little to do outdoors. If a thaw exposes the ground, a quick look at the guards is worthwhile. Indoors, listen for mice, which may need separate attention.
Early spring, as the snow goes: walk the yard and mark the damage with flags or photos. Resist the urge to rake hard. Wait until the lawn starts to grow, then repair bare patches and clear flattened runways.
Through the first growing season: watch the shrubs and young trees. A plant that leafs out late or only on one side may have been girdled partly. Decide on replacement once you can see what lives.
Are voles a problem inside the house?
Rarely. Voles are mainly lawn and garden animals, and house mice are the likelier culprit for droppings, gnawing and scratching indoors. Field mice and voles near open land can wander into sheds and garages in autumn, so edges of town see more of them. A technician can tell which animal you have.
The confusion is natural, because the animals look alike and both move toward buildings as the weather turns. Field mice, which are a separate group from house mice, may enter a shed or garage on the edge of a field. Voles themselves mostly stay in the grass.
If you hear movement inside, think mice first and read our guide on when mice come in. If the trouble is in the lawn, the treatment is different, and combining the two in one visit is common for houses at the edge of a suburb. Pages for areas such as Eden Prairie and Inver Grove Heights describe what open land does to a lawn.
Frequently asked questions
Will my lawn grow back after vole damage?
Usually, though slowly. Extension says grass usually recovers slowly and that damaged areas often fill in as surrounding grass grows into them. Reseed bare patches if they stay open, and avoid hard raking before growth starts.
Can voles kill a tree?
Extension says woody plants can be killed, usually when bark is removed all the way around the base. A tree gnawed on one side may survive. Guards set in autumn protect young trees best.
Is it too late to protect plants once the snow has fallen?
Mostly yes for this winter, since the damage happens under the snow where you cannot see it. Guards can still be fitted in a thaw, but the best time is before snowfall. Plan for next year.
How can I tell voles from moles in my lawn?
Voles leave surface runways in the grass and chew bark; moles push up raised tunnels and mounds. A photo helps a technician tell the difference over the phone.
Do I need pesticide for voles?
Extension's guidance leans on habitat control, barriers, traps and, where many plants need protecting, repellents. A technician explains what suits your yard and confirms the price before starting.
Do neighborhoods near open land see more vole damage?
It is reasonable to expect more cover, and therefore more voles, near fields, wetlands and tall grass, though we have no sourced comparison between Twin Cities neighborhoods. A yard with a mulched bed and a brush pile is a likelier target than a bare one.
Sources
- University of Minnesota Extension – How to manage vole damage on lawns, trees and shrubs
- University of Minnesota Extension – Protecting trees and shrubs in winter
This guide is general information for Hennepin County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.