Why Is My Tree Bark Peeling Off? Causes, Diagnosis, and Management in Calgary
- Sprig The Tree Geek
- 22 hours ago
- 4 min read
Tree bark acts as your tree's first line of defense. It protects against insects, disease, harsh weather, and physical damage while helping move water and nutrients throughout the tree. So when bark starts peeling or falling away, it's understandable to wonder if your tree is in trouble.
The truth is that peeling bark isn't always a sign of a dying tree. In some cases, it's completely natural. In others, it can signal environmental stress, disease, insect activity, or physical damage that should be addressed before the tree's condition worsens.
If you've noticed bark peeling from a tree on your property, Evergreen LTD can inspect the tree, determine what's causing the damage, and recommend the right course of action to protect its long-term health.
Some Trees Naturally Shed Their Bark
Before assuming the worst, it's important to identify the tree species.
Certain trees naturally shed layers of bark as they grow. Paper birch and some poplar species regularly peel thin layers of bark, revealing fresh bark underneath. This process is a normal part of their growth and doesn't affect the tree's health.
However, many other tree species should not lose bark in large sections. If the exposed wood appears dry, damaged, or continues expanding over time, it's worth having the tree evaluated by a certified arborist.
Calgary's Weather Can Damage Tree Bark
Calgary's climate creates unique challenges for trees throughout the year.
Cold winters, sunny winter afternoons, and rapid temperature swings can all contribute to bark damage. One of the most common problems is sunscald, which typically affects the southwest side of a tree trunk. During sunny winter days, the bark warms up before temperatures quickly drop overnight. This repeated freezing and thawing can damage the living tissue beneath the bark, eventually causing it to crack or peel away.
Frost cracks can develop in a similar way, leaving long vertical splits in the trunk. Young trees and recently planted trees are especially vulnerable because their bark is thinner and provides less protection.
Physical Damage Can Lead to Bark Loss
Mechanical injuries are another common cause of peeling bark.
Lawn mowers, string trimmers, construction equipment, or even wildlife can remove bark from the trunk. Once the protective bark is gone, the exposed wood becomes vulnerable to insects, decay, and fungal infections.
Unlike our skin, trees cannot grow new bark over damaged areas. Instead, healthy trees gradually seal the wound by forming protective tissue around the edges. The larger the wound, the longer this process takes and the greater the risk of additional problems developing.
Protecting the trunk from unnecessary damage is one of the simplest ways to improve a tree's long-term health.
Diseases Can Cause Bark to Crack and Peel
Peeling bark can also be a symptom of disease.
One example is Cytospora canker, a fungal disease commonly found on Colorado spruce, one of Calgary's most popular evergreen trees. As the disease progresses, homeowners may notice cracking bark, resin flowing from the trunk or branches, and branch dieback.
Many fungal diseases take advantage of trees that are already stressed by drought, winter injury, or physical damage. Once a tree's natural defenses are weakened, disease becomes much easier to establish.
Because several diseases produce similar symptoms, an accurate diagnosis is essential before deciding on treatment.
Insects Often Target Stressed Trees
Insects rarely attack healthy trees first.
Wood-boring insects are most likely to infest trees that are already weakened by drought, injury, or disease. As they tunnel beneath the bark, they interfere with the tree's ability to transport water and nutrients, causing sections of bark to loosen or fall away.
Although Alberta has avoided the widespread emerald ash borer damage seen in eastern Canada, other bark-boring insects can still create significant problems for stressed trees.
Maintaining tree health remains one of the best ways to reduce the risk of insect infestations.
Drought Stress Can Weaken Bark
Calgary's dry climate places additional stress on landscape trees, especially during extended periods without rainfall.
Young trees are particularly vulnerable because their root systems are still developing. Without adequate moisture, trees become less capable of defending themselves against insects, disease, and environmental damage.
Deep watering during dry periods, combined with proper mulching around the root zone, helps support healthy growth while improving resistance to stress.
When Should You Call an Arborist?
Peeling bark should never be ignored when it's accompanied by other signs of decline.
It's time to schedule a professional inspection if you notice:
Large sections of bark falling away.
Dead or dying branches.
Oozing sap or resin.
Fungal growth on the trunk.
Small holes that may indicate insect activity.
Bark missing around most or all of the trunk.
When bark has been removed around the entire circumference of the tree, the flow of water and nutrients can be severely disrupted, greatly reducing the tree's chances of recovery.
Protect Your Trees Before Small Problems Become Bigger Ones
Peeling bark doesn't always mean a tree is dying, but it should never be dismissed without understanding the cause. Whether the issue stems from natural growth, Calgary's challenging climate, physical damage, insects, or disease, identifying the problem early gives your tree the best opportunity to recover.
If you're concerned about bark peeling on a tree in your yard, Evergreen LTD's ISA Certified Arborists can provide a professional assessment, identify the underlying cause, and recommend the most effective solution.
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