Don’t Let This Commonly Overlooked Winter Danger Ruin Your Fruit Trees

Winter conditions can be challenging for many types of plants, including young fruit trees. While harsh weather can cause damage, many gardeners forget to think about hungry creatures that may target your trees when food sources become more limited. For example, rabbits may ignore your newly planted apple tree all summer, munching on tastier plants around your garden instead. However, in midwinter, you may discover that the bark has been stripped off all the way around the base. 

When food is scarce, the bark and softer outer layer of wood become a prime food source for rabbits and rodents such as mice and voles. These creatures are collectively responsible for significant damage to fruit trees, other young trees, and even shrubs every winter. Fortunately, you can outwit them with a few timely precautions. Take a few minutes this fall to protect your young fruit trees. Come spring, you'll be glad you did.

How Wildlife Damage Fruit Trees in Winter

On older fruit trees, the bark is rough and protective. Younger trees, on the other hand, are favorite targets for rabbits and mice and are very susceptible to damage. These creatures use their sharp teeth to gnaw and strip the bark and the soft layers directly underneath (the xylem and phloem), which are used to transport water and nutrients.

Removing this layer restricts the tree from moving water up from the roots or nutrients back down, a process known as girdling. It’s such an effective way to kill trees that it's often used on invasive species as a quick way to solve the problem without having to chop the whole thing down. 

Most girdled trees will die within the first growing season, even if they eventually leaf out in spring. If the tree is only partially girdled, it may survive, but even a slight amount of bark stripping is detrimental because it exposes the tree to disease and hinders growth.

Rabbits feed on exposed bark above the snow line (if you have snow). Mice and voles will gnaw the tree from under the snow or use the cover of long grass or thick mulch. Their damage is usually lower, at the soil level, although they may climb up to keep feeding a few inches from the ground. Young trees are the most vulnerable while their bark is still thin, smooth, and easy to strip. Once a tree trunk reaches a few inches in diameter and the bark becomes thicker and rougher, it is no longer as appealing. 

Winters with higher snowfall are often more hazardous for young trees, particularly with regard to mouse and vole damage. The thick blanket of snow protects mice and voles as they tunnel under it to reach food, while staying hidden from predators. Rabbits, with their large hind paws, can stand atop the snow to reach higher portions of tree trunks. Heavy snow also makes other food sources harder to forage, causing rodents and rabbits to turn toward bark nibbling.

Prevention Strategies

Prevention is the only effective method to protect against rodent or rabbit damage. Once they’ve fed on your young fruit tree, it’s likely too late. Prevention strategies fall into two categories: making it difficult for animals to reach the trees, and reducing the habitat immediately around the trees to encourage destructive critters to move elsewhere.

Protection

Protection, or making it hard to gnaw the bark, involves covering the lower portion of the trunk. 

• 1/4-inch hardware cloth is the most effective protection against rabbits and also serves as a deterrent for mice. Do not use ½-inch hardware cloth, as it allows the animals to slip through.
• Cut a piece and roll it to make a cylinder or tube. To cut a long enough piece of hardware cloth, multiply the desired diameter by 3.14. For example, to make a hardware cloth circle with a 5-inch diameter, you need 5 inches x 3.14 = 15.7 inches of hardware cloth. Give yourself an extra inch or two for some overlap. Fasten is around the trunk with a few pieces of wire (an old coat hanger works great). If you can, bury the bottom edge several inches below ground level to prevent critters from digging underneath.
• Alternatives to DIY tree protectors are tree guards and tree wraps, which are commonly available at hardware stores and garden centers. They are easy to install each autumn and need to be removed in the spring.

Habitat Modification

Habitat modification makes the area around fruit trees a less attractive and less inviting space for mice, rabbits, and voles. 

• Mulching around fruit trees is important to insulate the trees against the cold, but rake mulch back one foot away from the stem so mice can’t burrow or hide in it at the base of the tree.
• Keep the grass around fruit trees trimmed short. Mice or voles like to hide in taller grass, feeling safe from predators like owls and hawks, or your neighbor’s cat.
• Remove tall weeds, brush piles, and other rabbit shelters near your fruit trees. Rabbits also hide behind boards stacked against the garage, in woodpiles, or even under your deck.

Less Effective Remedies

There are numerous other yet unproven methods for protecting young fruit trees. Many people swear by a particular home remedy for rabbits, such as coffee grounds, pet urine, garlic, or even strongly scented soap. While a rabbit might not enjoy these items, when they’re starving, anything goes.

Mouse traps work in the house, but you may find them less effective outdoors. The same applies to other mouse and rodent remedies, such as poison or live traps. Remember, we share our outdoors with many creatures, and a poison or trap may harm beneficial wildlife.

Though chicken wire cages are moderately effective against rabbits, they are completely ineffective against mice and voles. Young rabbits can also squeeze through the holes in chicken wire. Scarecrows, plastic owls and snakes, flashy pinwheels, and wind chimes are also of questionable efficacy.