What Causes Tree Bark To Split Vertically?

Seeing the bark of a great tree crack vertically may be both awe-inspiring and unsettling. What we call “bark cracking” “bark fissuring,” or simply “vertical splitting,” is the development of large, linear cracks running vertically up and down the surface of the trunk.

It may look like a normal aspect of an old tree’s development, but it could be a sign of serious problems that could compromise the tree’s health and stability.

tree trunk

This article will explore the causes of vertical bark splits and how they can be prevented. With this knowledge, arborists, tree fans, and homeowners can take preventative actions to ensure the safety of their trees and maintain their aesthetic value for years to come.

Join us as we investigate the environmental, biological, and anthropogenic causes of vertical bark splitting and learn about viable preventative and corrective measures. Let’s delve into the fascinating world of trees and learn what makes each species’ bark pattern and behaviour so special.

What Causes Tree Bark To Split Vertically?

Environmental, ecological, and human influences all play a role in the development of vertical bark splits on trees. The following are some of the more prevalent explanations for this observation:


  • Environmental Stress: Extreme weather conditions, such as sudden temperature fluctuations, prolonged drought, or severe frost, can cause the bark to split vertically. When the outer layers of the bark expand and contract at different rates, it creates tension within the bark, leading to fissures.


  • Sunscald: Sunscald occurs when the bark is exposed to intense sunlight during the winter months, especially on the south or southwest side of the tree. The dark-coloured bark absorbs more heat, which can cause the living cells just beneath the bark to become active. When freezing temperatures return at night, the active cells freeze and burst, resulting in vertical cracks.


  • Age and Growth Rate: As trees age, their bark gradually loses elasticity, making it more prone to splitting. Additionally, rapid growth spurts, often seen in young trees or those with sudden bursts of growth, can lead to bark fissures due to increased pressure on the outer layers.


  • Pest and Disease Infestation: Insects, fungi, and bacteria can attack the tree’s bark, causing it to weaken and crack. Certain pests, like borers, can tunnel through the bark, leaving behind damaged tissue. Fungal infections can also degrade the integrity of the bark, making it susceptible to splitting.


  • Mechanical Damage: Physical injuries to the tree’s trunk, such as accidental cuts from landscaping equipment or animal scratches, can create wounds that weaken the bark’s structure and pave the way for vertical splits.


  • Tree Species: Some tree species are naturally more susceptible to bark splitting than others. For instance, some types of oak trees are known to exhibit vertical fissures as a regular part of their growth pattern.


  • Improper Pruning: Incorrect or excessive pruning can disrupt the natural growth and strength of the bark. Improper cuts can lead to bark damage and create entry points for diseases and pests, increasing the likelihood of vertical splitting.


  • Root Issues: Problems with the tree’s root system, such as root girdling or damage, can impact the tree’s ability to transport nutrients and water. As a result, the tree’s overall health may decline, making the bark more vulnerable to splitting.


Accurate diagnosis of the cause is crucial for the effective treatment of vertical bark splitting in trees. Bark splitting can be prevented to some extent and the long-term health of trees can be promoted by proper care, such as regular inspections, proper pruning techniques, and prompt treatment of pests and diseases.

If you want to know what’s wrong with your tree and how to fix it, a trained arborist is a good resource to tap into for this kind of information.

How Do You Fix Splitting Bark On A Tree?

Repairing a tree with peeling bark demands a thorough evaluation of the situation and the implementation of measures to facilitate healing and forestall additional damage. Some solutions to the problem of bark splitting on tree are as follows.


  • Assessment: First, assess the extent of the damage and determine the cause of the splitting. If the splitting is severe and widespread, or if it’s caused by a disease or pest infestation, it’s best to consult a certified arborist to evaluate the tree’s health and recommend appropriate treatment.


  • Clean and Trim: Remove any loose or damaged bark around the split to prevent it from further tearing or becoming a potential entry point for pests and diseases. Use a clean, sharp pruning tool to make clean cuts along the edges of the split.


  • Promote Wound Healing: Applying a wound dressing or sealant is generally not recommended, as research has shown that trees naturally heal more effectively without such products. Instead, allow the tree to compartmentalize the wound naturally.


  • Support and Protect: For smaller splits, you can use flexible tree wraps or fabric straps to gently support the bark and hold it in place while it heals. This helps reduce tension in the damaged area and prevents further splitting.


  • Address Underlying Issues: If the splitting is due to environmental stress, such as sunscald or extreme weather conditions, consider providing shade or mulching around the base of the tree to regulate soil temperature and moisture. For pest or disease issues, consult with a professional arborist to implement appropriate treatment measures.


  • Avoid Pruning Too Close: During future pruning, be mindful not to cut too close to the trunk, as this can damage the bark and create new wounds.


  • Maintain Proper Irrigation: Adequate watering, especially during dry periods, can help maintain the tree’s overall health and reduce stress on the bark.


  • Monitor the Tree: Regularly inspect the tree for signs of improvement or any new issues that may arise. Patience is key, as bark healing is a gradual process that may take several months or even years, depending on the severity of the damage.


Keep in mind that if the split is large or the tree’s health is poor, it may not be possible to entirely repair the bark. The health of the tree and its ability to recover from the injury may be prioritised in specific situations. If you want to know what to do with a tree in your yard, it’s best to consult a professional arborist.


Environmental stress, sunscald, age, growth rate, pest and disease infestation, mechanical damage, tree species attributes, inappropriate pruning, and root difficulties are all potential causes of vertical splitting in tree bark.

If you want to solve the problem and improve the tree’s health and longevity, you need to get to the bottom of what’s causing it.

It is important to determine the severity of the damage and rule out other potential causes of the tree’s distress while dealing with cracked bark. If you want to make sure you’re doing the right steps, consulting a trained arborist is a must.

To treat splitting bark, clean and trim the area, but don’t bother with wound dressings or sealants; trees usually recover on their own. Tree wraps or straps can help the healing process by providing support and protecting the bark.

Treating the tree’s roots, keeping it well-watered, and using mulch or shade to moderate the soil’s temperature are all helpful in bringing the tree back to health.

Even if some bark cracks can’t be completely repaired, it’s still important to make sure the tree is healthy and vibrant in other ways. Bark healing is a gradual process, so regular monitoring and patience may be required.

Leave a Reply

Your email address will not be published. Required fields are marked *