How to Protect Trees from Winter Bark Damage

Winter Bark Damage: The Hidden Threat

While winter seems like a dormant season for trees, bark damage during cold months is one of the leading causes of tree decline. Three primary threats target tree bark in winter: sunscald, frost cracks, and animal browsing. Understanding each helps you protect your investment.

Sunscald: When Winter Sun Burns Bark

Sunscald occurs when dark bark heats up on sunny winter days, then rapidly cools at night. The temperature swing kills living tissue beneath the bark, creating sunken, discolored patches. Young trees with thin bark are most vulnerable.

• Most common on southwest-facing trunk sides
• Appears as sunken, cracked, or peeling bark in spring
• Affects newly planted trees and thin-barked species most
• Maple, apple, honeylocut, and linden are high-risk species

Prevention: Tree Wraps and Guards

Commercial tree wrap (crepe paper or polyethylene) reflects sunlight and insulates the bark. Install wraps in late fall, starting at the base and spiraling up to the first branches. Remove in spring to prevent moisture buildup and pest habitat.

Frost Cracks: Explosive Bark Splitting

Frost cracks are vertical splits that can extend several feet up a trunk. They form when the outer bark contracts faster than the inner wood during rapid temperature drops. A loud "crack" sometimes accompanies the split — it can sound like a gunshot.

While frost cracks rarely kill a tree, they create entry points for disease and decay organisms. Trees with previous frost crack damage are more likely to crack again in the same spot each winter.

Animal Damage: Rodents and Deer

Hungry voles, rabbits, and deer find tree bark an attractive food source when other options are scarce under snow cover. Voles tunnel under snow and gnaw bark at ground level, while rabbits reach bark up to 12-18 inches high.

• Install hardware cloth cylinders around young tree trunks
• Extend protection 18-24 inches above expected snow line
• Bury the bottom 2-3 inches to prevent burrowing underneath
• Remove guards in spring to avoid trunk girdling as the tree grows

Mulching for Winter Root Protection

A 2-3 inch layer of organic mulch around the tree base (not touching the trunk) insulates roots against temperature extremes and retains soil moisture. This indirect protection helps the entire tree, including the bark, withstand winter stress.

Watering Before the Freeze

Trees entering winter with adequate moisture resist bark damage better than drought-stressed trees. Provide deep watering in late fall until the ground freezes, especially for evergreens and recently planted specimens.

Taking these protective measures before the first hard frost significantly reduces the risk of winter bark damage. Healthy bark means a healthy tree come spring.