What Trees Lose Their Bark? And When It’s Normal

Many trees shed their bark as a completely normal part of growth, and the list is longer than most people expect. Sycamores, birches, eucalyptus, crape myrtles, shagbark hickories, madrones, and dozens of other species routinely peel, flake, or exfoliate their outer bark throughout their lives. The process is driven by the same basic mechanism in nearly all of them: as the trunk expands, the rigid outer bark can’t stretch to keep up, so it cracks and falls away. What matters for anyone worried about a tree in their yard is not whether bark is coming off, but how it’s coming off, which species you’re looking at, and whether other symptoms are present.

How Bark Shedding Works

Bark isn’t a single layer. Beneath a tree’s outermost dead bark sits a living tissue called the periderm, which acts as the tree’s primary protective boundary with the outside world. The periderm includes a thin layer of dividing cells called the cork cambium (or phellogen), which produces corky, waterproof cells outward and a thin layer of living cells inward.¹ These three components together form the tree’s replacement “skin” once its original surface can no longer keep pace with expansion.²

In many tree species, the periderm regenerates in successive layers deeper inside the trunk as the tree ages. The older, outermost layers lose their connection to living tissue and eventually crack, peel, or flake off. This is what you see when a sycamore drops pale, jigsaw-shaped plates onto your lawn or when a birch’s papery sheets curl away from the trunk. The tree isn’t injured. It’s outgrowing its old coat.

How bark separates varies by species and depends on the structure of the dead outer layers. Trees with thin, papery outer bark tend to peel in sheets. Trees with thick, corky bark tend to crack into furrows and shed in chunks or strips. Trees with rigid, inflexible outer bark that can’t stretch at all tend to shed in dramatic mosaic patterns, exposing smooth inner surfaces.

The Most Common Bark-Shedding Trees

If you’ve noticed peeling bark and want to know whether your tree is on the “this is just what they do” list, here are the species that shed most visibly.

• Sycamore and London plane: American sycamores (Platanus occidentalis) and London plane trees (Platanus × acerifolia) are probably the most recognizable bark shedders in temperate climates. Their outer bark is unusually rigid and cannot expand, so it cracks and falls off in large irregular patches, revealing a pale, almost white or greenish inner surface. A mature sycamore in summer often looks like it’s wearing camouflage.
• Birch: Paper birch (Betula papyrifera), silver birch (Betula pendula), and river birch (Betula nigra) all peel in thin, papery horizontal sheets. The color of the peeling bark varies by species, from brilliant white to salmon-pink to cinnamon brown. Silver birch bark in particular has been studied for its complex chemistry, including the production of betulin and suberin through specialized metabolic pathways that vary even among closely related species in the birch family.³
• Eucalyptus: Many eucalyptus species shed bark annually, and the results are often stunning. Smooth-barked species like the rainbow eucalyptus (Eucalyptus deglupta) reveal bright green, orange, and purple layers beneath the shed strips. Others, like the scribbly gum (Eucalyptus haemastoma), shed in small flakes that expose insect tunnels left behind by moth larvae, creating the “scribbles” on their trunks.
• Crape myrtle: Lagerstroemia species shed thin strips of bark from their trunks and major branches, revealing smooth, mottled surfaces in shades of tan, gray, and cinnamon. This is considered one of their most ornamental features, and it’s entirely normal year-round.
• Shagbark hickory: Carya ovata earns its common name honestly. Long, vertical strips of bark separate from the trunk and curl outward at the top and bottom, giving the tree a distinctly shaggy appearance. The strips can be a foot long or more. This is not damage; it’s the species’ signature look.
• Paperbark maple: Acer griseum peels in translucent, cinnamon-colored sheets that glow when backlit by the sun. It’s a relatively small tree prized in landscaping precisely because of its exfoliating bark.
• Pacific madrone: Arbutus menziesii, native to the Pacific Northwest coast, sheds its outer bark in late summer to reveal a striking lime-green to reddish-orange smooth surface. The peeling is dramatic and rapid, often happening over just a few weeks.
• Lacebark pine: Pinus bungeana sheds bark in rounded flakes, creating a patchwork of white, green, gray, and brown that intensifies as the tree matures. It’s one of the few pines that exfoliates this way.

This list isn’t exhaustive. Scotch pine, certain elms, bald cypress, and many tropical species also shed bark regularly. If you can identify your tree and it’s on or near this list, the peeling is almost certainly normal.

Seasonal Patterns and What Triggers Shedding

Bark shedding tends to be most obvious during the growing season, roughly late spring through early fall in temperate climates. That’s when the trunk is actively expanding, putting the most mechanical stress on the outer layers. In species like sycamore and madrone, the heaviest shedding often coincides with summer heat and periods of rapid growth.

Drought and heat can accelerate shedding in some species. When bark dries out, it loses flexibility, cracks sooner, and separates more readily. You might notice more flaking in an unusually hot, dry summer. Conversely, a wet spring that fuels fast growth can push bark off sooner simply because the trunk is expanding quickly.

For eucalyptus species, shedding often follows a consistent annual cycle tied to the tree’s growth rhythms. Some eucalypts shed their entire trunk bark once a year, while others shed in irregular patches throughout the season. In any case, a eucalyptus dropping bark in summer is behaving exactly as expected.

Winter isn’t immune either. Shagbark hickory’s curling bark plates stay on the tree year-round and shed gradually, so you may find pieces on the ground during any season. And birch bark peels throughout the year, though it’s more conspicuous in winter when the white or cinnamon trunk stands out against bare branches.

When Bark Loss Signals a Problem

Normal bark shedding reveals healthy tissue underneath: smooth, often brightly colored, and firmly attached to the trunk. Problem bark loss looks different. Here are the signs that something is wrong rather than routine.

• Exposed wood looks dark, wet, or mushy: Healthy exfoliation reveals living inner bark or a clean, dry surface. If the exposed area is dark brown, black, or oozing, that usually means fungal infection or bacterial canker. Diseases like hypoxylon canker can cause bark to slough off in large sheets, exposing rotting wood beneath.
• Bark is falling off a species that doesn’t normally shed: If your oak, maple (other than paperbark maple), ash, or similar tree is suddenly dropping bark, it’s worth investigating. These trees do develop furrows and sometimes lose small pieces, but large-scale peeling is unusual and may indicate sunscald, frost cracking, or disease.
• Small holes in the bark or sawdust-like material at the base: This points to boring insects like bark beetles or emerald ash borers. The beetles tunnel beneath the bark, weakening the cambium layer, and the bark above their galleries can fall off in pieces. You’ll often see tiny round or D-shaped exit holes.
• Bark separating at the base of the trunk near the soil line: Root rot and collar rot caused by fungi like Phytophthora can kill bark from the bottom up. If bark near the ground is loose and the wood underneath smells sour or looks waterlogged, the tree likely has a serious root problem.
• Long vertical cracks with dead tissue beneath: Frost cracks and sunscald injuries happen when winter sun warms one side of the trunk during the day, then temperatures plummet at night. The bark splits, and the edges may die and peel back over time. This is common on young trees with thin bark, especially those with southwest-facing exposure.

The general rule is straightforward: if you know the bark is peeling and the species is one that normally exfoliates, relax. If the species shouldn’t be shedding, or the exposed tissue looks unhealthy, have an arborist take a look.

Sunscald and Frost Damage on Young Trees

Young trees with smooth, thin bark are particularly vulnerable to a kind of bark damage that mimics natural shedding but isn’t. Sunscald happens in winter when direct afternoon sun heats bark on the south or southwest side of the trunk, activating cells out of dormancy. When temperatures drop sharply after sunset, those active cells freeze and die. The dead bark eventually cracks and peels away.

This is most common in thin-barked species like young maples, cherries, honey locusts, and lindens. The damage typically appears as a long, sunken area on one side of the trunk, sometimes with the bark peeling back to reveal dried, dead tissue. It can be prevented by wrapping the trunks of newly planted trees with reflective tree wrap during their first few winters, or by planting where buildings or other trees provide afternoon shade.

Frost cracks are a related phenomenon. Rapid temperature swings cause the outer bark to contract faster than the wood beneath it, producing a vertical split. These cracks can be a foot long or more and may open and close repeatedly across winters. The tree often heals each season by producing callus tissue along the edges, only to have the same crack reopen the following winter. While this isn’t the same as natural exfoliation, the peeling bark edges around a frost crack can look similar to a casual observer.

What Lives Under Peeling Bark

Loose, exfoliating bark creates microhabitats that are ecologically valuable. The gap between peeling bark and the trunk provides shelter for a surprising array of wildlife. Spiders, beetles, centipedes, and moth larvae all overwinter or hide under bark flaps. For some species, loose bark is critical habitat.

Certain bat species rely on exfoliating bark for roosting. A study tracking northern bats (Myotis septentrionalis) in the Midwest found that nearly half of the 32 roost trees used by the bats were roosts under exfoliating bark, with silver maples being a preferred tree. The rest roosted in crevices or hollows, and over half the roost trees were living rather than dead.⁴ This is one reason wildlife managers sometimes prioritize retaining large trees with shaggy, peeling bark in forests managed for biodiversity.

If you’re tempted to strip loose bark off a tree to “clean it up,” consider leaving it. You’re not helping the tree by removing bark that hasn’t fully detached on its own, and you may be evicting residents. The bark will fall when it’s ready.

Birch Bark and Its Cultural History

Birch bark’s tendency to peel in large, flexible sheets made it one of the most useful plant materials available to Indigenous peoples across the Northern Hemisphere. Archaeological work on the Canadian Plateau of British Columbia has documented birch bark containers and other artifacts made by prehistoric First Nations. Ethnographic records from the region indicate that birch bark basketry was consistently produced by women and served essential roles in food collection, storage, and ceremonial life, including girls’ puberty rituals and burial practices.⁵

Birch bark canoes, of course, are among the most famous applications. The bark’s natural waterproofing, lightweight flexibility, and availability in large sheets made it ideal for boat construction across boreal and subarctic regions. The same chemical properties that make birch bark waterproof, including its high suberin content, also make it resistant to decay, which is why birch bark artifacts survive in the archaeological record far better than most other plant-based materials.

Eucalyptus bark has a different cultural footprint. Aboriginal Australians used large sheets of shed bark from stringybark eucalyptus species to build shelters, make carrying vessels, and create shields. In some regions, the bark was also used as a surface for painting, producing artworks that are now held in major museum collections. Both birch and eucalyptus bark could be harvested specifically because these trees naturally produce large, cohesive sheets rather than crumbling fragments.

An Extremely Ancient Trait

Bark shedding isn’t a modern evolutionary curiosity. Fossil evidence shows that trees were shedding bark at least 230 million years ago. Exceptionally well-preserved permineralized stems of Kykloxylon, the wood associated with the iconic Dicroidium seed ferns of the Gondwanan Triassic, were collected from the Middle to Upper Triassic Helliwell Formation in the Transantarctic Mountains of Antarctica. Some of these fossil logs show cavities filled with multi-layered periderm, and isolated flakes of shed bark matching this periderm in cell shape and dimensions are abundant in rock samples from multiple coeval sites.⁶

The fact that bark shedding was already “profuse” in Triassic seed ferns suggests that the process has been independently evolved or maintained across very different plant lineages over vast spans of time. The selective advantages are likely multiple. Shedding bark can remove parasites and epiphytes (mosses, lichens, and climbing plants) from the trunk surface. It can help regulate moisture loss. And in fire-prone environments, shedding the outermost flammable layers may reduce the chance that fire spreads into the living tissues of the trunk. The consistency of this trait across hundreds of millions of years and across unrelated lineages hints that it provides meaningful survival benefits, even if the specific advantage varies by habitat.

Practical Tips for Homeowners

A few things are worth knowing if you’re managing bark-shedding trees on your property. First, the mess is real. Sycamores and eucalyptus in particular can drop enormous volumes of bark, and it doesn’t decompose quickly. Some homeowners rake it up, while others use it as mulch or leave it. Either approach is fine for the tree. Just know that bark debris under a sycamore is a seasonal feature, not a one-time event.

Second, resist the urge to peel bark that’s partially attached. Pulling bark off prematurely can tear into living tissue and create a wound that invites infection. If a strip is dangling and bothering you, cut it cleanly at the point where it’s still firmly attached rather than ripping it downward.

Third, crape myrtles have become the subject of a specific landscaping controversy. Some gardeners aggressively peel the bark off crape myrtles each season, believing it encourages new growth or a neater appearance. The tree doesn’t benefit from this. Its bark will shed on its own schedule, and forced peeling can damage the thin living layers beneath. The same applies to the widely criticized practice of “crape murder,” or severe annual pruning, which is a separate issue from bark shedding but often accompanies overzealous trunk grooming.

Finally, if you’re planting a new tree and bark texture matters to you, the exfoliating species are genuinely some of the most ornamental trees you can grow. Paperbark maple, lacebark pine, crape myrtle, and river birch are all widely available in nurseries and valued specifically for the visual interest their peeling bark provides across seasons. The shedding that alarms some homeowners is the same feature that landscape designers pay a premium for.