Deer, rabbits, and voles
Three animals, three fences. Why an 8-foot deer barrier, a buried rabbit apron, and hardware cloth for voles are not interchangeable.
A single roll of garden fencing does not deter “wildlife.” Deer jump, rabbits chew at snow line, and voles work underground and under mulch. Each one makes a different kind of damage, and each one is stopped by a different mesh at a different height.
Repellents are a supplement when pressure is light and a waste when a hard winter has removed the wild forage. Plant lists marketed as deer-proof are a menu deer consult and then ignore in March. Fence first. Choose plants second.
Deer
Deer browse leaves, buds, and tender stems, often overnight, and they come back to a plant they liked.
Colorado State University Extension’s fact sheet on preventing deer damage says the conventional deer-proof fence is 8 feet high and made of woven wire. The mountain vegetable fact sheet gives the garden version: a minimum of 8 feet, or a double fence of two 4-foot fences set 4 feet apart.
Electric fencing is the next step where pressure is heavy, and CSU specifies high-tensile wire and a charger that actually holds voltage, not a decorative strand. A 4-foot picket is not on either list. Fence the food garden. Fencing the whole lot is a different project, priced in fence and hail-frame materials.
The bottom of a deer fence should be tight to the ground or the deer will push under, especially fawns. A gate that is left open one night is the night the beans disappear. Electric wire is an option on the top or as a standalone system if local rules allow it and you will maintain the charge. A sagging electric wire is not a fence.
Repellent sprays wash off in the thunderstorms the Colorado Vegetable Guide already warned you about. They can protect a shrub for a week in light pressure if you reapply.
They will not protect a row of peas in May when a doe is feeding a fawn. Motion lights and radios habituate. A dog in the yard at night works until the dog sleeps inside.
Some plants are eaten less often. Daffodils and many alliums are poor forage. Tulips, hostas, roses, and beans are not. A “resistant” shrub will be sampled.
In a hard winter it may be eaten to the snow. Use resistant plants outside the fence for the ornamental yard, and put the food inside.
The Front Range and high plains lists are for climate, not for deer immunity.
Rabbits and hares
Rabbits clip seedlings cleanly and girdle bark at the snow surface in winter. CSU’s mountain vegetable fact sheet says a 2-foot fence of 1-inch mesh, with the bottom buried 6 inches, keeps cottontails out.
Gilpin County Extension says at least 2 feet, buried 4 to 8 inches. Use the buried bottom.
A deer fence of wide cattle panels does not stop a rabbit unless you add that small mesh along the ground. They will not jump the 8-foot wire. They will walk through a 6-inch gap.
In winter, the snow becomes the new ground surface. A two-foot fence buried in a drift is a zero-foot fence. In snow country, raise the rabbit mesh or use a taller cylinder around individual trunks.
Hardware cloth, quarter-inch or half-inch, formed into a cylinder around a young fruit tree, is the trunk guard that stops rabbits and voles together. It should stand above the expected snow and sit slightly off the bark so it does not rub. Remove or enlarge it before the trunk grows into it.
Habitat matters. Brush piles against the garden fence are rabbit cover. A clean edge and a mowed strip make the fence more effective.
Live-trapping and relocating is a poor plan and is often illegal. Check local wildlife rules before you set any trap. A fence is the legal, durable tool.
Voles
Voles are small rodents that travel in tunnels under grass, mulch, and snow. They eat roots, bulbs, and the bark of trees and shrubs at or below the soil line.
You see the damage in spring as a girdled trunk or a tree that leafs out and then collapses.
They are not moles. Moles eat insects and make raised tunnels.
Voles use those tunnels and eat plants. Poison bait in an open garden is a risk to pets and to other animals and is not the first tool. Habitat and exclusion are.
Pull mulch back from trunks. CSU’s vole fact sheet says to encircle young trees and shrubs with quarter-inch hardware cloth, 18 inches above the ground and 3 to 6 inches below the surface. A straw blanket against the bark is a feeding station, not a kindness. The mulch page covers the moisture reason for the same gap.
In a vegetable bed or a strawberry bed with a known vole problem, lay quarter-inch hardware cloth under the soil or under a raised bed, turned up at the edges.
The mesh has to be open enough for water. It is a floor, not a plastic liner. Raised beds without a floor are not vole-proof. The animals live in the ground the bed sits on.
Reduce cover in winter where you can: long grass against the garden, boards left flat on the soil, and unused row cover piled at the edge. Mow a strip.
In a bad year, trapping in protected stations is the extension-recommended next step, done so birds and pets cannot reach the trap. Follow the current note from your extension office. Do not broadcast bait.
A fence that matches the lot
For a typical Front Range or valley lot with deer in the evening and rabbits year-round: an 8-foot fence around the vegetable and fruit area, mesh small at the bottom or a rabbit apron, gates that close, and trunk cylinders on any fruit tree outside that fence.
For a plains lot where deer are rare and rabbits and wind are the issues, the rabbit fence and the windbreak matter more than 8-foot posts. For a mountain cabin that is empty in April, the fence has to work without you. Repellents will not be reapplied. Build the fence before the first season of peas, not after.
Check the fence in fall. Deer test the weak corner. Rabbits find the gap the mower opened. Voles move in when the mulch goes down.
A Saturday in October with a roll of wire saves the trees you will not see again until May.
Checklist
- Use an 8-foot woven-wire deer fence, or two 4-foot fences set 4 feet apart, as CSU specifies.
- Use a 2-foot fence of 1-inch mesh, buried about 6 inches, for cottontails.
- Raise rabbit protection to the snow line in winter.
- Put quarter-inch hardware cloth around trunks and under vole-prone beds.
- Keep mulch off bark.
- Treat deer-resistant plant lists as hints, not fences.
- Reapply repellents only as a supplement, and do not rely on them in a hard winter.
- Walk the fence before you plant in spring and again when you mulch in fall.
Sources
- CSU Extension, Colorado Vegetable Guide, on wind, hail, and the general need to protect plantings. Local wildlife notes from CSU, USU, and MSU Extension are the current local specification for fence details and for any trapping rules.
- University of Idaho Extension, BUL 859 and BUL 936, on site protection as part of gardening in harsh climates.
- CSU Extension, Preventing Deer Damage, 8-foot woven-wire fence.
- CSU Extension, Vegetable Gardening in the Mountains, rabbit mesh, the double 4-foot deer fence, and hardware cloth under beds.
- CSU Extension, Managing Voles in Colorado, quarter-inch cylinders 18 inches above ground and 3 to 6 inches below.