How can I prevent deer browsing and feeding during the winter months?
Deer may feed on trees and shrubs during the winter months and severely damage or destroy plants. Damage is most likely to occur when food is scare during prolonged periods of snow cover. Deer often feed on the foliage on the lower branches of arborvitae, pines, and other evergreens, but also feed on other plants especially when food is scarce. Prevention is key to managing this damage.
Prevention if the most important way to avoid damage from deer to trees and other garden plants.
Tree Guards, Tubes, & Wire Cylinders
Tubes, wraps, wire fencing, and wire cylinders can be placed seasonally around individual trees and shrubs to physically exclude and prevent deer from browsing. When placed early in the fall, they are also often effective at preventing damage from antler rubbing. Guards, tubes, and cylinders are not permanent structures and need to be removed in spring. They are most effective on smaller, younger plants that are more susceptible to significant damage from deer feeding. These structures should be at least six feet tall. Wire cylinders can be shorter for smaller plants as long as they are closed on top.
Exclusion with fencing materials is the most effective, albeit often most costly, method to prevent deer from eating and otherwise damaging garden plants. Fencing can be permanent for year-round protection or temporarily installed in the fall to prevent damage during the winter months. Woven wire or mesh fences are good options as they are durable, flexible, and easy to install across a variety of terrains. To protect an entire garden area, fences must be at least 8 feet tall. If the area that needs to be protected is smaller than 8 feet by 16 feet, a shorter fence of 50 inches can be used to exclude deer since deer will not jump into a small, fenced enclosure.
Electric fencing made from electrical wire or polytape can be used to deter deer from entering a garden area. Deer must be trained to avoid the fence by baiting it with peanut butter spread on aluminum foil and folded over the wires. The light shock that comes when they sample the bait will deter them from coming near the fenced area. Flags or bright colored polytape help make the fence more visible to deer and people in the area. Check local regulations before installing an electric fence as they may be prohibited in your area.
Fishing line can be used as a simple and visually unobtrusive way to deter deer from entering a garden area. String high-test (30 lb. +) monofilament fishing line tightly around a garden bed at least two feet beyond the outside edge and 36 inches above the ground. Deer encounter the fishing line in the dark making them feel uncomfortable and then avoid the area. Inspect the line often for breakage. This method works on a short-term basis and for areas that have low deer density. It is not effective for areas that see daytime feeding where deer would be able to see the fishing line.
Repellents can provide short-term protection for smaller garden areas. Repellents work in one of two ways - as a contact repellent, like capsaicin, applied directly to the plant to make it tase unpleasant or as an area repellent, like predator urine, that deter deer because of an unpleasant odor. Change the scents and types of repellents on a regular basis to prevent deer from getting used to the scent and ignoring it.
Apply repellents early and often when conditions are dry and temperatures are above freezing. Apply sprays from a height of 6 feet down since deer typically browse from the top down. Over the winter months, repellents have limited success at preventing deer browsing because reapplication can be difficult in freezing temperatures.
Changing the garden in ways that make it less attractive to deer can help reduce browsing damage. Plant highly desirable plants in areas with more human activity. Utilize more deer resistant plants near garden edges or near places where deer are more likely to browse such as near wood lots. Never feed deer in your area. While this management approach is not very effective on its own, it can help when combined with other management techniques.