There’s a Hole in My Tree! What Does it Mean?

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Holes in trees can be disconcerting. Many homeowners are unsure about what holes indicate for tree health, or what they should do when a hole appears. In this post, we address tree holes and talk about how a hole could be a sign of compromised structural integrity. We discuss different kinds of holes that may be found, as well as how and why they occur. Although holes are not always a sign that there is something wrong, it is best not to take chances. If there’s a hole in your tree, be sure to contact a licensed and insured Portland tree care company to learn about potential structural damage.

Tree with woodpecker holes and a squirrelAre tree holes hazardous? They can be if they cause the structural integrity of the tree to fail. If this happens, the whole tree or one of its main branches may plummet to the ground, which could lead to injury and/or property damage. On the other hand, many tree holes do not present a problem, and do not necessarily need to be filled. In fact, our Portland arborists warn against filling holes with concrete (which was frequently recommended in the past), because this can actually lead to more problems.

If you are concerned about the hole for aesthetic reasons, there are foams that arborists now use to fill holes. These foams work better than concrete, as they allow more movement when the tree sways. But these foams cannot improve structural integrity; they are solely for aesthetic purposes. If there is a problem with the tree’s structural integrity, an arborist has other tools at her/his disposal, which can include cabling, bracing, propping up, or removal.

Let’s look at some common forms and causes of tree holes.

Splits and Cracks. Oftentimes a tree will form a split or crack in its trunk. Splits pose serious problems as they place stress on the structural integrity of the tree. Once a crack starts, it is likely to grow, as the tree buckles and sways in the wind. This is why it’s important to address them as early as possible. Cabling may be effective, but if the problem is too severe, you might need to remove a limb or even the entire tree. Our arborists also provide safe and effective tree removal services for split trees that can’t be salvaged.

Mushrooms and Fungi. Fungi growing at a tree’s base suggest there may be a larger problem. Hollows can also be signs of fungal infection. Since some fungi are benign, and others are harmful, it is best to let an arborists make the call and offer their expert advice.

Sapsucker and Woodpecker Holes. These destructive birds chip away at tree bark to access tree sap and resident insects. Woodpeckers and sapsuckers can do serious damage as they bore small holes in trees. While these birds don’t kill trees, their feeding can weaken them and leave them more susceptible to diseases and insect infestation.

Tree Hollows. These are often caused by fungi and can be a sign that there is decay inside the tree, which can ultimately lead to a loss of structural integrity. Squirrel holes can also be indicative of a problem.

Often a tree has holes but it is unclear if they are big enough to cause problems. Determining the structural integrity of a tree is as much an art as it is a science. Professional arborists use specialized tools to evaluate tree strength. One of these tools is called a Resistograph. It uses a small drill to test density. Trained arborists can conduct tests and carry out procedures to prevent damage and prolong a tree’s lifespan. Inspection and monitoring are key to ensuring the safety and long-term survival of the trees on your property.

Be sure to call a certified arborist today if you see evidence of structural damage or are worried about tree holes. Our ISA-certified arborists have the skills, expertise, and tools to make the right call regarding the health and well-being of your trees.

[Photo by synspectrum via CC License]

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