⚠ Moderate Urgency

Bark Peeling or Splitting on Trees

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What It Means Causes Trees Affected How Urgent What To Do Call an Arborist?Regional Notes Related Pests FAQ

What This Symptom Usually Means

Bark protects the tree's living tissues from disease, insects, and weather. When bark peels or splits, the cause determines the urgency. Some species (sycamore, birch, crape myrtle) naturally shed bark as part of normal growth — the exposed inner bark looks smooth and healthy. Problematic bark loss reveals dry, brown, or decayed wood and is caused by frost cracks, sunscald, canker diseases, boring insects, or mechanical damage.

Most Likely Causes

Natural bark shedding

Sycamore, birch, crape myrtle, paperbark maple, shagbark hickory, and certain pines naturally shed bark. Exposed bark is smooth, colorful, and healthy-looking.

Frost cracks

Vertical splits in the trunk caused by rapid temperature changes in winter. Sun warms the bark during the day, then sudden cooling at night causes the wood to contract and crack.

Sunscald

Bark on the south or southwest side of young trees dies from winter sun exposure. The dead bark eventually falls off, exposing wood to decay.

Canker diseases

Fungal or bacterial infections that kill patches of bark, creating sunken, discolored areas. Cytospora, Nectria, and Hypoxylon are common canker-causing organisms.

Boring insects

Bark beetles, emerald ash borer, and wood borers tunnel under the bark, causing it to crack, peel, and fall off. Look for small holes and sawdust.

Mechanical damage

Lawn mowers, string trimmers, vehicle impacts, and animal damage strip bark. These wounds are entry points for disease and decay.

Trees Commonly Affected

Sycamore

Natural bark shedding is normal — reveals white inner bark

River Birch

Exfoliating bark is a desirable ornamental feature

Maple

Frost cracks and sunscald common on young maples

Ash

Bark splits from emerald ash borer galleries underneath

Cherry

Horizontal lenticels and peeling bark are natural features

Apple/Crabapple

Canker diseases cause significant bark loss

How Urgent Is This?

⚠ Moderate Urgency

Varies. Natural bark shedding is not urgent at all. Frost cracks and sunscald are moderate — they weaken the tree over time but are not immediately dangerous. Active cankers that are girdling the trunk or main branches are high urgency. Boring insect infestations (especially emerald ash borer) can be critical and require immediate action.

What You Can Do Right Now

Determine if the bark loss is natural for the species — research your tree's normal bark characteristics.
Check exposed wood: healthy and moist is usually okay; dry, brown, or soft indicates a problem.
Look for small holes, sawdust, or frass under the peeling bark — signs of boring insects.
Protect young trees from sunscald with trunk wraps applied in fall and removed in spring.
Keep lawn mowers and string trimmers away from the trunk — use a mulch ring instead.
Do NOT apply wound sealant or paint — research shows this slows natural healing.

When to Call a Certified Arborist

Contact a certified arborist if any of these apply:

✓Bark loss exposes dry, discolored, or decaying wood
✓Cankers (sunken dead areas) are expanding or girdling the trunk
✓You find bore holes or sawdust under the bark
✓A frost crack extends more than 3 feet or has been opening wider each winter
✓Bark is peeling on a species that does not normally shed bark

Find an Arborist Near You

State & Regional Differences

Midwest

Frost cracks are extremely common due to wide winter temperature swings. EAB is causing bark splitting on ash trees throughout the region.

Southeast

Hypoxylon canker is a major bark disease, especially on oaks stressed by drought. High humidity promotes many canker-causing fungi.

Southwest

Sunscald is common on thin-barked trees planted in full sun. Bark beetles thrive in drought-stressed conifers.

Northeast

Beech bark disease is a significant problem. Winter damage to bark is common in exposed locations.

Frequently Asked Questions

Is it normal for tree bark to peel off?

For some species, yes. Sycamore, birch, crape myrtle, paperbark maple, shagbark hickory, and certain pines naturally shed bark. Healthy-looking, smooth inner bark underneath is a good sign. Dry, brown, or soft wood underneath the peeling bark indicates a problem.

Should I seal a tree wound where bark has come off?

No. Research has consistently shown that wound dressings and tree paint do not help healing and may trap moisture and disease organisms. The one exception: fresh oak wounds during oak wilt season (April-July) should be sealed immediately with pruning paint to prevent beetle vectors from accessing the wound.

Can a tree heal after losing bark?

Trees do not heal like humans — they compartmentalize damage by growing new wood around the wound. A tree can survive bark loss on less than 50% of its circumference. Complete bark loss around the entire trunk (girdling) is fatal because it severs the tree's nutrient transport system.