Winter deer damage can be one of the biggest risks to landscapes and mature trees and shrubs in areas with high deer populations. As temperatures drop in late September the risk of deer browsing to woody ornamentals and evergreens begins to increase. These are plants that are normally not targeted by deer in the spring and summer, but become vulnerable as food sources dwindle in the fall and through the winter. Hungry deer can cause significant damage and disfigurement to plants, and in some cases plant loss if preventative measures are not taken.
As we move into October we will see an increase in deer activity as deer start to bulk up for the winter, and breeding season (the rut) begins. The peak of the deer rut can vary based on weather, but typically reaches its height around November 13th. Deer will be very active at dawn and dusk during this time, and risk of automobile accidents involving deer increases tremendously. This is also when male deer will rub their antlers on shrubs and trees as they attempt to remove the velvet covering on their antlers. They also do this to mark their territory and attract breeding does. Deer prefer to rub on smaller trees that are typically less rigid. Wrapping tree trunks with guards in the early fall can help prevent antler rub damage, which in some cases can seriously impact smaller trees.
Deer digestive systems will begin to change in the late fall to be able to digest “roughage” such as twigs, buds, and less tender evergreen plant material. As annual and perennial flowers begin to die off, and lawns go dormant, the deer will adapt to available food sources to ensure survival. Deer will often utilize acorns and other nuts as part of their diet, so a high mast(nut) production year for these trees can lessen deer pressure on trees and shrubs. When this change occurs is ultimately dictated by the change in weather conditions, and can happen anywhere from mid-October to early December. Pressure on these plants will persist up until March/April. Heavy snow cover can reduce the height of fencing meant to deter deer, and plants that are normally deer resistant can become targets for browsing.
Deer pressure is also strongly impacted by weather conditions. Last year we had a particularly cold winter with higher than normal levels of snowfall. We saw heavy damage as a result of the colder temperatures, and the heavy snow prevented deer from reaching acorns and other low lying food sources. The properties that deer were present on experienced significant damage, however the heavy snow did reduce deer traffic and kept deer from moving from property to property with ease. Weather predictions for this winter are for colder than average temperatures with slightly higher than average precipitation. We likely wont see snow accumulations like we did last year, but cold temperatures will keep deer hungry and in search of calories to burn to keep warm.
Make sure that you have taken the proper measures to protect your plants from deer this fall and winter or you may risk losing them. SavATree can provide treatment options for clients with concerns about winter deer damage.