Plum trees are highly attractive features in many landscapes because the fruit’s high sugar content provides an easy, concentrated energy source as the plums ripen. A successful harvest requires understanding which animals are drawn to the sweet fruit and implementing management measures. Protecting the crop involves accurately identifying the offenders and strategically applying physical barriers and environmental controls.
Identifying the Common Plum Predators
Identifying the specific culprit causing damage is the necessary first step before selecting a protection strategy. Different animals leave distinct clues, allowing the grower to determine which predator is responsible for the lost harvest.
Arboreal pests like tree squirrels often partially eat fruit and drop it directly beneath the tree. Squirrels may also strip bark from the trunk or larger branches, especially when other food sources are scarce.
Nocturnal animals, such as raccoons and opossums, typically cause extensive damage overnight, sometimes stripping many plums in a single visit. They often rip fruit from the plants or break smaller limbs while climbing. Deer damage differs because they lack upper incisors, leaving a ragged edge on browsed twigs or fruit.
Avian pests, including starlings, robins, and crows, leave small, irregular peck marks on the fruit’s skin. These punctures allow diseases, like brown rot, to enter the fruit. Terrestrial predators, including deer and bears, are particularly destructive to the tree itself. Deer browse low-hanging branches, while bears may cause significant limb breakage or strip the entire crop by climbing.
Exclusion Using Physical Barriers
Physical exclusion is often the most reliable method for protecting a plum harvest, as it directly blocks access to the fruit. Bird netting is a common solution, but mesh size is an important consideration for effectiveness and wildlife safety. While a mesh size of 0.62 inches by 0.62 inches is effective for excluding most birds, some jurisdictions recommend a tighter mesh (5 millimeters or less) to prevent the entanglement of smaller wildlife. The netting must be draped completely over the tree and securely fastened at the trunk to prevent access by climbing animals like raccoons and opossums.
For protection against deer, the height of a perimeter fence is the most significant factor. An 8-foot barrier is generally required to exceed the animal’s jumping capabilities. An alternative for individual trees is a circular cage constructed of welded wire, which does not need to be 8 feet tall because the small enclosure prevents the deer from gaining the necessary space for a jump. Trunk protection, such as metal wraps or plastic cones, can be installed around the lower trunk to prevent squirrels and raccoons from climbing. This method is effective only if the tree’s canopy does not touch adjacent structures or other trees that would allow pests to bypass the barrier.
Deterrence and Environmental Management
Deterrence methods discourage animal feeding through unpleasant sensory experiences rather than physical blockage. Repellents generally fall into two categories: taste-based and scent-based, and both require consistent reapplication, particularly after rainfall.
Taste-based repellents often use capsaicin or bitter agents to make the fruit unpalatable. Scent-based products use strong odors, such as predator urine or rotten egg solids, to signal danger. These non-physical methods are most cost-effective when damage is light or moderate and when only a few applications are necessary for control.
Environmental management, or sanitation, is a passive yet highly effective form of deterrence, especially against nocturnal foragers. Ripe and fallen fruit attract raccoons and opossums, who are drawn to the easy meal and the insects gathering around the decaying matter. Promptly cleaning up all dropped fruit beneath the tree removes the primary attractant, making the area less appealing. Motion-activated sprinklers or reflective tape are sometimes used as scare tactics, though animals often habituate to these auditory and visual devices over time, reducing their long-term effectiveness.