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What Causes a Tree Trunk To Split Vertically?

What Causes a Tree Trunk To Split Vertically?

When you notice a vertical crack on your tree’s trunk, one of the many questions you might ask yourself is, “What causes a tree trunk to split vertically?”

In this blog post, Collegeville’s tree service company delves deeper into vertical splitting in tree trunks to help you understand its cause and remedies.

Tree Trunk Splitting: Common Reasons

One of the common causes of vertical splits in tree stems concerns frost cracks or sunscalds.

What’s a frost crack?

This vertical crack affects a tree’s bark and wood and appears on the trunk or branches during winter. It results from the tree’s inability to withstand the expansion and contraction of its bark and wood due to the freeze/thaw cycle of water in its tissues.

Since water expands upon freezing, it occupies more space. Unfortunately, your tree’s bark and wood can’t stretch enough to provide room for the expanding water. As a result, the tree will develop cracks as the water molecules in its cells expand.

You’ll often experience vertical cracking in tree bark on the west and south sides of trees. Why is that so?

These sides experience longer periods of warm sunlight before the colder temperatures at night. Note that small frost cracks hardly cause severe damage to trees. Your tree may survive several years with the split trunk. However, the vertical cracks make your tree more vulnerable to various diseases and other harmful organisms.

Insects can also turn the frost cracks into their breeding ground while feeding on your tree. Large cracks can increase the likelihood of your tree falling, causing injuries and property damage.

How To Repair a Split Tree Trunk

Now that you know what causes a tree trunk to split vertically, let’s see how you can fix the problem. If your tree’s trunk hasn’t split into two, and only the bark has a crack, follow these steps to repair the issue:


You’ll need to drill about three holes through the cracked section of the tree trunk. Next, insert bolts through the holes. Be sure to have large washers on the bolt ends to provide adequate surface areas for enhanced support.

Remove the Wound

You can also fix a cracked trunk by removing the wound entirely. Start with removing the bark edges and then cut around the damaged area. This approach helps accelerate the healing process.

When you remove the wound, you allow the tree to transport essential nutrients efficiently. Don’t interfere with healthy bark and expose more live tissue to harm.

Contact Your Local Tree Experts for Assistance

Do you want to learn more about what causes a tree trunk to split vertically? Maybe you need help with understanding vertical tree trunk damage or factors behind tree trunk vertical cracks. Beyond the Leaf Tree & Shrub Experts can help.

We provide a wide range of services, including:

  • Hazardous Tree Assessments
  • Tree Pruning
  • Tree Removal

Call us at (888) 606-3382 for a free estimate or to learn how we deal with thick tree branches in Collegeville, PA, today!