Key Features
- Chewed foliage
- Teeth marks on trunk
- Rows of holes on trunk
Symptoms
Animal feeding removes entire leaves, bunches of leaves, or sections of bark over the course of minutes to hours where it would take most diseases or swarms of insects days or weeks. Signs of the animals presences can accompany the damage; tufts or hair, footprints, feces, or even signs of "force" such as broken branches, antler scrapes, or teeth and claw marks can all help to identify the cause of the damage. The location of the damage can also help identify the culprit. Rodent damage will occur within 10 inches of the ground while deer browse and rubbing will not generally reach above 5 feet. Sapsuckers and woodpeckers feed primarily on stressed trees and branches that are infested with boring insects. Squirrel damage is most frequently observed on thin-barked branches that are large enough for the squirrel to comfortably sit on.
Biology
In the spring, deer feed on young, succulent tree leaves. In the summer, male deer scrape bark from trees using their antlers. Evergreen trees such as arborvitae are highly susceptible to deer browse in the winter when there is little else to eat. Other examples of animal damage include holes in the bark from sapsucker and woodpecker feeding, branch bark peeled back by squirrels, and girdling (a chewed ring of bark and wood around the trunk) caused by rabbits, mice and voles.
Management Recommendations
Use fencing or tree guards to protect susceptible trees from destructive animals. Avoid tight fitting guards because they can increase damage caused by boring insects and canker pathogens. Products containing putrescent egg solids are effective in repelling deer for a short time but should not be used where people may be exposed to the terrible smell. Remove weeds and keep grass mowed low; this limits hiding places for small animals and a food source for deer. Maintain mulch levels at 2-3 inches and avoid excessive mulch levels and volcano mulching which provides habitat for rodents.
Effective Pesticides
Pesticides are neither available nor recommended for managing this condition.
Resources
