Although damage to trees is widespread in years when rabbit numbers are high, it can be significant locally even in years when the rabbit population is low on a statewide basis. Winters of deep snow are usually accompanied by heavier damage. Although tree bark is a major rabbit food only during December to February, considerable amounts of it may be eaten any time from the first killing frost of the fall until mid-April.
Trees Preferred: Of the deciduous trees, those with thin bark such as willows, poplars, and apple are most frequently attacked by rabbits. However, maples and ash are susceptible until they are past the sapling stage of growth. Walnut and oak are generally ignored by rabbits. Among the conifers, pines are definitely preferred over firs and spruce.
Rabbit Evidence: Rabbits may debark a tree from as low as an inch above the soil line or snow line to as high as they can reach standing on their hind legs. Debarked areas should show the marks of the rabbits incisor teeth. On trees of sapling size, the tooth marks will run horizontally since the rabbit must turn its head sideways to bring the teeth into good gnawing position. Sightings of rabbits or their tracks or droppings within a tree plantation should be reason enough for an inspection of individual trees for signs of gnawing damage.
Preventing the Problem: Fencing is the most effective method of protecting an area from rabbits. Use a fence of chicken wire 36 inches high with several inches buried in the ground. Individual trees can be protected with cylinders of woven or welded wire set so that there are at least two inches between the tree and wire at all points. Wrapping the trunks of individual trees will discourage rabbit attacks but may be too time consuming for a tree plantation. Commercial tree wrap and heavy aluminum foil are equally effective. Wrap each tree as high as rabbits can reach standing on top of the expected snow cover.
Rabbit Repellents: Repellents will usually protect trees for an entire winter or about two months at other times of the year. They should be applied in the late fall when temperatures are above freezing so that the material will dry on the bark rather than freeze on. A homemade repellent can be made by dissolving seven pounds of lump rosin in one gallon of alcohol. Apply the mixture to the trunk and low branches of the trees with a paint brush.
The winter landscape may seem a bit bland at first glance. But if you look closely, you'll find that quite a few plants have interesting bark that is actually easier to appreciate without the distraction of leaves and flowers. Bark often changes over time, so that a species that starts out with thin, smooth bark on twigs and young branches may become thick and flaky or change in color as the plant matures. Beautiful bark comes in many forms, including smooth, shiny, ridged, flaky, blocky or peeling.
Among the better-known candidates for ornamental bark are the birches, the paper bark birch (Betula papyrifera) most obvious. As the tree gets a few years of age, the outer white bark peels off in horizontal sheets to reveal reddish-brown bark beneath. There are several other birch species with attractive bark, including European white birch (Betula pendula) with white, non-peeling bark eventually mottled with black, sweet birch (Betula lenta) with shiny, reddish-brown bark and river birch (Betula nigra) with peeling, scaly bark mottled with cinnamon brown, beige and orange.
Some of the most beautiful bark belongs to the cherry (Prunus) species, many of which are lustrous, shiny and characterized by horizontal grayish-brown markings that are very distinctive. The native black cherry (Prunus serotina) has attractive grayish-black bark, but, due to its prolific production of seedling offspring, can be quite a nuisance species. Nanking cherry (Prunus tomentosa) is a shrubby cherry with reddish-brown, shiny and peeling bark.