Grazing Grief
It seems as if white-tailed deer are a ubiquitous pest and there is almost no time of year we can escape damage occurring to our landscape plants from their foraging. While it may seem as if no plant is safe from grazing, deer do have food preferences although they vary dependent on season and availability. Deer have very seasonal feeding patterns, their diets will change drastically from winter to summer. Primary spring and summer forage for deer includes forbs, grasses, crops, leaves twigs and buds. While mast, such as beech nuts, cherries and acorns makes up the majority of their fall diet. Winter foraging focuses almost entirely on twigs, buds and bark but broad-leafed evergreens are never entirely safe. A deer’s body goes through changes in the fall to be able to digest this woody plant material, and during the growing season deer will almost always leave woody plants alone as it is not necessarily preferred food. As soft plant material comes available in the spring, they will actually switch back to eating grass, annuals and perennials. Within 1 to 2 weeks, feeding on woody ornamentals and evergreens completely stops. The amount a deer needs to consume (which may translate into damage to your landscape plants) depends on their age, sex and the season. In general deer need to consume approximately 3% of their body weight per day. So a buck weighing in at 125-250 lbs will require 4,000 to 6,000 calories per day which can be obtained from up to 10 lbs of grass or twigs. In our home gardens and landscape deer will be attracted to flowers, fruits and vegetables and the buds and twigs on fruit trees and ornamental trees and shrubs. Damage to your landscape plants can certainly occur year-round, but during late winter and early spring the damage may be the worst due to the shortage of other food supplies. A period of high deer pressure in June/July is typical, which is largely driven by hot temperatures and lack of available water sources. Extensive fruit tree damage could cause the loss of the current crop and residual injury and stress could limit future yield. Ornamentals can suffer permanent disfigurement at the hands (or really mouths) of deer.
Browsing Behavior
There are some common landscape and garden plants especially preferred by deer and therefore have the potential to experience frequent severe damage. For a complete list visit http://njaes.rutgers.edu/deerresistance/. Using some of the plants in the rarely damaged category in and amongst your other landscape material could aid in preventing or limiting the extent of damage to your plants. Also, consult with your arborist to see if the use of deer repellents or resistant products is warranted or could be useful on your property. Generally deer will tend to avoid plants with strong smells, fuzzy or rough leaf textures or variegation. Deer have delicate and sensitive olfactory receptors, so plants with strong odors will be repellent to deer. Fuzzy, rough-textured foliage and leathery leaves are not as palatable due to the offensive texture.
