Preventing Winter Wildlife Damage in the Garden
By Emma Erler UNH
Extension Education Center Program Coordinator
A mark of a healthy garden and landscape is a diversity of wildlife species. But as nice as it is to have animal visitors in the garden, some have the potential to cause significant damage during the winter months if precautions aren’t taken.
Meadow voles and white-tailed deer are two of the most destructive pests once snow is on the ground. Ensure that your landscape plants make it to spring unscathed by protecting them from these pesky winter critters.
Meadow voles are one of the most significant winter rodent pests in the garden. Voles are compact rodents with stocky bodies, short legs and short tails. Their eyes are small, and their ears are typically partially hidden.
They are very common in grassy fields and lawns, and are active both day and night, year-round. In the spring and summer, voles eat living plants such as grasses, sedges and herbaceous weeds. In the fall and winter, they switch their diet to seeds, tubers, bulbs and tree bark when other foods are unavailable.
Vole feeding often results in girdled branches, trunks and roots, which can kill trees and shrubs if the damage is extensive. Their feeding habits can be problematic for gardeners who have planted spring bulbs or new trees.
Tulips and crocus are among their favorite bulbs to eat, and apple, blueberry, peach, plum, cherry, maple and juniper are vulnerable to damage from girdling. Young trees are especially susceptible to meadow vole feeding.
You can reduce vole populations in your yard and garden by eliminating weeds, ground covers, leaf litter and excess mulch from around the bases of trees. Keeping the lawn mowed regularly also helps.
These actions expose voles to predators by not giving them anywhere to hide. Voles are much less likely to spend time feeding in areas where they feel exposed.
Young trees and shrubs can be protected from girdling by putting guards around them. It’s easy to construct your own tree guards with materials that can be found at any hardware store. All you need is galvanized hardware cloth (1/4-inch mesh) and wire.
Place cylinders of hardware cloth around the lower trunks of trees and wire them snuggly shut. Dig them several inches into the ground to keep voles from tunneling beneath.
The cylinders should be large enough to accommodate at least five years of growth, at which point the tree should be less susceptible to feeding damage. Aim to have tree guards rest above the anticipated snowline (at least 24 inches) to keep voles from climbing over or through the snow to reach tree bark.
Certain types of bulbs are especially appealing to voles and other wildlife. Freshly planted tulips and to a lesser extent crocus are regularly devoured.
The only surefire way to prevent this from happening is to exclude wildlife. Use half-inch galvanized hardware cloth to create cages to protect bulbs. Place bulbs inside of the cages with the root end down and bury the entire cage at the proper planting depth.
When done properly, rodents will be unable to access the bulbs. Repellents can also be effective if they are applied to the soil at the planting site, but they must be reapplied frequently, particularly after every rain.
White-tailed deer are thriving in New Hampshire, in part because they are incredibly adaptable when it comes to habitat. Deer can live just as successfully in rural woodlands as they can on farmlands or in suburban gardens. Urban deer are especially problematic as they have few predators and hunting is often not an option where homes are closely spaced.
While it’s clear the deer are here to stay, that doesn’t mean there isn’t anything you can do to stop them. Fortunately, there are three key strategies you can implement to limit deer damage in your garden this season.
Excluding deer from the garden is the most successful management tool gardeners can employ. A good fence is a gardener’s best friend where deer are concerned.
Electric fencing is one effective option. A single shock may be enough to train a deer to keep away from the garden. Just make sure the fence is visible to both deer and people.
A startled deer may run through an electric fence that it can’t see. If you are concerned about pets or children contacting an electric fence, you can try constructing an upright fence instead.
The height of an upright fence is its most important feature. White-tailed deer can jump up to 8 feet high, so fences must be at least this height. There are literally dozens of fencing materials that will work including wood, wire, mesh and heavy-duty plastic netting.
If there is one particular plant in the landscape that deer frequently browse on, you may find that it is more economical to build a cage around that individual plant. Simply drive a few stakes into the ground and surround those securely with mesh.
Evergreen plants that deer find appetizing, like arborvitae and holly, can be wrapped with burlap to protect them from winter winds and deer browsing. Applying repellents is another way of dealing with deer.
The efficacy of repellents depends on how they are used, and reapplication is often necessary. Many repellents lose their effectiveness after rainfall or simply after a certain amount of time.
New growth that isn’t protected by a repellent may be in danger. Even in the best of circumstances, repellents will never eliminate deer damage but only help reduce it.
Contact repellents are applied directly to plants. Although mode of action differs, most deter deer by odor, taste or both. These should only be used on plants that are not for human consumption. There are many commercial formulations available, all of which should be applied and used as specified in the instructions.
Area repellents are those that can be placed in the vicinity of plants and whose odor is enough to deter deer browse. These types of repellents are usually less effective than contact formulations.
Bar soap and garlic “sticks” are frequently clipped or hung from the branches of plants that deer enjoy. If deer are only an occasional issue in your garden and there is plenty of other good stuff for them to eat nearby, you may find that area repellents will do the trick.
When all else fails, try growing plants that voles and deer largely ignore. When planting spring bulbs, choose types that are seldom bothered by wildlife such as daffodils, snow drops, glory-of-the-snow, Siberian squill, grape hyacinth and allium.
And, while yews and arborvitaes are generally irresistible to deer, spruce, fir and American hollies are largely avoided. Deer tend to avoid plants that are hairy, spiny tough or particularly aromatic.
The most important thing to remember is that all wildlife-proofing methods are more effective when they are used before problems start. Once animals learn to associate your garden with tasty plants, they will keep coming back.
However, if you deter them from your yard and garden early in the season, you’ll save yourself a lot of frustration and your garden will have a chance to thrive.
Got questions? UNH Cooperative Extension Education Center’s Info Line offers practical help finding answers for your lawn and garden questions. Call toll-free 877-398-4769, Monday through Friday,
9 a.m. to 2 p.m., or email firstname.lastname@example.org.