Do you have a hollow tree? If so, here are some tips to consider whether it should be cut down.
In late October, we removed a silver maple that had blown over during a storm with high winds.
“The wind blew it over and it turned out to be hollow,” said one of our crew members, of the silver maple. “The force was so strong that it drove a gas meter two feet into the ground and smashed up the roof.”
Certain species of tree are prone to hollowing, and silver maples are one of them. Trees with cracks and holes are a sure sign that a tree is starting to hollow out. That doesn’t automatically mean it will fall. However, it does indicate that it’s more likely.
A tree can become hollow from various forms of stress or damage such as:
- Insect infestation
- Human damage (concrete, lawn mowing, weed whacking)
Other times the tree will cause the damage itself. An older tree may self-prune by losing lower branches. This area will have a higher risk of forming a cavity.
A well-maintained tree is better able to deal with stressors, making it much less likely to become hollow.
The common question is: should I cut down my hollow tree? First, ask yourself the following:
- How big is the hollow and where is it located on the tree?
- How old is the tree?
- Besides the tree being hollow does the tree look healthy?
- Does the tree look structurally sound or is it leaning?
- Is there anything under the tree that is important? House, car, kids!!
If your tree has a hollow area it can still be healthy. A rule of thumb for a maple is that it needs one inch of healthy wood, observed as the diameter, for every 6 inches of circumference. Larger trees, bigger than 40″ around, need more healthy wood than a smaller tree.
Cut down the tree if:
- The hollow area is extremely large and the tree is old or unhealthy. Young or healthy trees should be able to adapt to the hollow areas, even if they are large, as long as everything else about the tree is healthy.
- If the tree is leaning or the base is nearly hollowed out, this constitutes a higher risk.
- You don’t like the tree anyway.
If you’re unsure, ask an arborist. An arborist will be able to determine the health and risks of the tree, giving you a proper assessment.
We do not recommend filling the hole. Most arborists believe you will damage the tree more than help it – by slowing down the development of included bark, a natural healing process for the tree.