A Question of the Week

Deer damage to landscape plants

White-tailed deer were remarkably destructive in many gardens and landscapes over the past winter, feeding heavily on trees and shrubs. Favorite winter food sources, such as arborvitae and rhododendron, and relatively deer resistant plants like holly, suffered from deer browse. In many cases, even proximity to a house was not enough to deter hungry deer. Although deer damage is incredibly frustrating, there are steps you can take to repair damaged plants and prevent deer from becoming a nuisance again in the future.

As long as trees and shrubs are healthy, they can sustain a considerable amount of deer damage and survive. Once growth resumes in the spring or early summer, lateral buds along the stems will produce new vegetative growth that will gradually replace what was lost. Since deer seldom make neat cuts when they eat the ends of branches, you should clean up injured stems by pruning down to the closest healthy new growth. Cuts made with sharp pruners are much more likely to heal properly than ragged wounds created by deer.

deer damaged landscape plants

Enhancing plant health by providing adequate irrigation and proper nutrition will also help trees and shrubs recover over the course of the growing season. Most landscape plants benefit from receiving at least one inch of water each week, either through rainfall or supplemental irrigation. If fertilizing, note that trees and shrubs absorb nutrients readily in the spring before growth starts, or in mid-summer after shoot-growth ceases. A soil test will help you decide what fertilizers to use.

The next step is to make sure deer avoid landscape plants in the future. Excluding deer from the garden with fencing is by far the most effective strategy. Electric fences work well, and a single shock may be enough to train a deer to keep away from the garden. However, if you’re concerned about children or pets coming in contact with the electric fence, you can construct a perimeter fence out of wood, wire or mesh. As long as the fence is at least eight feet high it should keep deer out of the area. If you have just one plant that the deer seem to find irresistible, you may find that it is more economical to build a wire cage around that individual tree or shrub. Since deer usually only browse on woody plants during the winter months, you may only need to have the cage in place during that season.

Applying a repellent is the next best way of dealing with deer. The efficacy of repellents depends on their mode of action and how they are used. Contact repellents are applied directly to plants and deter deer through odor, taste, or both. Repellents that trigger a fear response are often most effective. These products generally contain putrescent egg solids, predator urine or slaughterhouse wastes, and may not be appropriate for use near heavily trafficked walkways or buildings. An alternative is placing area repellents in the vicinity of affected plants, such as bar soap or garlic “sticks.” These repellents are usually clipped or hung from the branches of trees and shrubs that deer enjoy. If deer are only an occasional issue in your garden, you may find that they provide enough protection. Even in the best of circumstances, repellents will never completely eliminate deer damage, but they can help reduce it. For best results, make sure to apply repellents according to the product label.

It is important to remember that all deer-proofing methods work best when they are employed early in the season. Although deer will largely switch to eating herbaceous plants once the growing season begins, it’s never a bad idea start deterring them from their favorite trees and shrubs before problems start again next winter.

Got questions? The Ask UNH Extension Infoline offers practical help finding answers for your home, yard, and garden questions. Call toll free at 1-877-398-4769, Monday to Friday, 9 a.m. to 2 p.m., or e-mail us at answers@unh.edu.

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Got questions? The Ask UNH Extension Infoline offers practical help finding answers for your home, yard, and garden questions.
Call toll free at 1-877-398-4769, Monday to Friday, 9 a.m. to 2 p.m., or e-mail us at answers@unh.edu.