Worms, weevils, rots, and molds are typically the first “evils” that come to mind when talking about pest problems in the fruit garden. Many gardeners, however, realize that wildlife pests can be just as problematic. Voles, mice, rabbits and deer keep fruit gardeners on their toes during the winter season. You can outwit them though. Knowing how particular wildlife behave will give you tools to help send them off to other foraging grounds.
Voles, mice, and rabbits normally do their greatest damage to fruit trees and bushes during the winter when food is scarce. They particularly enjoy the tender bark of young fruit trees. As rodents feed on the tree bark, they can girdle the plant near its base. Several preventive steps can be taken, as winter approaches:
● Late fall mowing of grass underneath and around trees or bushes reduces winter nesting sites near the fruit garden.
● Raking mulch back, away from the trunk, is another deterrent to rodents establishing winter nests.
● Wrapping young trees’ trunks with 1/4 inch hardware cloth or plastic spiral guards designed for this purpose can help protect them. It is important that the guard touch the soil surface so rodents do not have access from below. They should also be tall enough, usually 18 to 24 inches, that mice traveling on the snow surface will not enter easily from above.
● Gardeners who paint their tree trunks with latex paint, for the prevention of sunscald [LINK] may also notice a reduction in rodent feeding. Some growers feel adding copper enhances the deterrent effect.
Know your pest —
What many gardeners call mice are actually voles. Voles are active at any time of day and mainly build burrows in dense vegetation on the soil surface. Thus, keeping a weed-free strip or area at least 4 foot in diameter around your fruit plants is a good idea. Voles will burrow through the snow and feed on tree trunks if there is suitable habitat in your garden. They may also feed on shallow roots just below the soil surface. Often this leads to damage that goes undetected until not much can be done to save a severely girdled tree.
Various Microtus species are found in different parts of the country. All are prolific breeders with high population numbers cycling over a 3 to 6 year time-frame. Voles are typically 5 to 8 inches from nose to tail tip, with coarse blackish to greyish-brown fur. They are relatively fat and round-bodied with stubby legs and small ears and eyes. More detailed information on
meadow voles and their management, check this out.
Rabbit damage to fruit gardens differs a bit form vole damage in that it is often found above the snow line. Once the garden is covered in snow for 10 days to 2 weeks or more and a crust is formed on the surface, rabbits are inclined to visit fruit trees and berry bushes or canes. Much like voles, they too will gnaw on the bark, just higher up on the plant. Rabbits will feed on young, tender bark as well as low– growing shoots. Rabbit feeding is characterized by being a clean 45 degree cut. They tend to leave mature, tough, older bark alone unless food is extremely scarce.
Tracks and tell-tale droppings will often give clues to their visit as well. Occasionally, I have seen rabbits form a burrow right within a sheltered bush; so pay attention to where the tracks lead. To deter rabbits, it is often necessary to be sure that tree guards reach sufficiently above the snow line. More on rabbit habits and control can be found here.
Deer can become a serious pest of the late winter-early spring garden. They often feed on garden plants when other food in their winter yards becomes scarce. In contrast to rabbits, deer feeding will be more of a ripping of the branch and higher up on the plant. We’ll have more on deer browsing and how to discourage it in early spring.
Tips for using rodent guards
● Use guards that are of sufficient length to provide protection above the snow line.
● Guards should be pushed an inch or so into the soil to discourage root feeding.
● Make sure spiral type guards are not stretched out by larger diameter trees leaving exposed trunk areas where rodents can still feed..
● Remove plastic guards in the spring and reapply them in the fall. If left in place, check to make sure they do not become hiding places for trunk boring pests.
● As trees grow and expand and guards settle into the soil, make sure that the soil is not confining the bottom of the guard and causing it to strangle the trunk below ground.