Apple trees are highly palatable to white-tailed deer, posing a significant threat to young orchards and established trees. Deer view apple trees and their fruit as a valuable source of nutrition, especially when other food sources are scarce. Understanding deer feeding behavior and implementing protective measures is necessary for successful apple tree cultivation. Damage can range from reduced fruit yield to the complete loss of the tree, requiring proactive defense wherever deer populations are present.
The Appeal of Apple Trees: What Deer Consume and Why
Deer consume various parts of the apple tree throughout the year, driven by seasonal nutritional needs. Browsing (eating buds and twigs) becomes severe during the winter months. Dormant terminal buds and new shoots offer a concentrated source of nutrients and energy that is otherwise limited in the winter landscape.
In the spring and summer, deer readily eat the new, tender growth and leaves. Young leaves are appealing because they contain natural sugars and are easier to digest than mature woody browse. In late summer and fall, ripening and fallen fruit become a major attractant due to their high sugar and carbohydrate content. This influx of sugars helps deer build fat reserves for the coming winter.
Male deer cause a different type of seasonal damage during the fall breeding season, known as the rut. Bucks rub their antlers on young trees, stripping the bark and damaging the underlying cambium layer. This behavior is not feeding; it is a way to remove velvet from antlers and mark territory. However, it frequently results in the complete girdling and death of the sapling.
Distinguishing Deer Damage from Other Pests
Identifying the cause of tree damage is necessary before implementing a control strategy. Deer browsing is characterized by a ragged, torn appearance on the tips of twigs and leaves. This is a defining trait because deer lack upper incisor teeth, forcing them to grasp and tear vegetation rather than making a clean cut.
Damage from pests like rabbits or rodents, in contrast, shows a neat, clean cut, often at a 45-degree angle. The height of the damage is another indicator, as deer browse between two and six feet from the ground. Smaller pests cannot reach this height, while livestock damage occurs higher or follows a different pattern.
Antler rubbing leaves a distinct vertical scrape mark on the trunk of saplings, often with shredded bark. This injury is concentrated on younger trees with flexible trunks, differentiating it from feeding damage. Finding heart-shaped hoofprints or clustered, oval fecal pellets near the tree base further confirms the presence of deer.
Implementing Physical Barriers and Repellents
The most reliable long-term solution for protecting apple trees from deer is installing physical barriers. A permanent perimeter fence must be at least 8 feet high to effectively exclude deer, as they can jump lower obstructions. Woven-wire fencing is highly effective, though it is a more expensive initial investment.
For individual trees or smaller orchards, temporary enclosures such as wire cages or mesh fencing can be used until the trees mature. Tree wraps or plastic tubing should be applied to the trunks of young trees to prevent fatal damage from antler rubbing in the fall. Securing the bottom of any fence close to the ground is important, as deer often attempt to crawl under a barrier.
Repellents offer a non-physical method of deterrence, but their effectiveness is variable and requires consistent management. They are categorized into contact and area repellents, each working through a different sensory mechanism. Contact repellents are taste-based (e.g., those containing putrescent whole egg solids) and must be applied directly to the plant material deer might eat.
Area repellents work by odor, using ingredients like blood meal or bone tar oil, and are placed near plants to create an unpleasant scent barrier. Repellents must be reapplied regularly, especially after rain or new tree growth, to maintain their protective effect. It is beneficial to alternate between different types of repellents to prevent deer from becoming accustomed to a single product.