My Tree is Hollow! Does it Need to be Removed?
- Oliver Lester
- 2 days ago
- 3 min read
It is not unusual to come across a hollow tree in the woods; however, coming across one on your own property often raises some concerns. The tree's location, condition, and overall state can help determine if removal is necessary. But first, understanding why a tree becomes hollow can help when deciding whether the tree is still safe or needs professional attention.
What Causes A Hollow Tree
Hollow trees are typically caused by fungus breaking down the non-living tissue known as the 'heartwood' in the center of the trunk. Heartwood provides structure for the tree through its inner core, while 'sapwood' is the living, porous outer layer that transports water and nutrients from the roots to the leaves.
Heartwood is naturally resistant to rot; however, when wood-destroying fungi enter the tree's central core through exposed wood, they soften and gradually consume the heartwood, leaving the tree hollow. Despite this, the sapwood can remain strong and support the weight of the tree canopy. Some trees can be completely hollow within and continue to live and even thrive for many years to come.
Benefits of Hollow Trees for Wildlife
For thousands of years, wildlife has utilized hollow trees for protection against predators and harsh weather conditions. Insects, birds, and even mammals are able to access small cavities in the tree trunk, expanding them to form their own shelters.
Across the world, these hollow trees provide numerous benefits for wildlife, including:
Hollow trees serve as essential nesting sites for various bird species and shelter for small mammals
Many hollow trees host insects and fungi, which can be vital food sources for birds and other wildlife
And the cavities offer protection from predators and harsh weather conditions, enhancing the survival rates of many species
When to be Concerned
As stated before, a hollow tree can often survive for years to come despite the structural defect. However, depending on the tree's location, size, and condition, it can be a cause for concern.
If any of these concerns arise, contact a certified arborist to assess the health of your tree:
The hollow of the tree takes up an extensive area, about 33% of the tree's diameter, shows the tree is no longer structurally sound
Mushrooms growing at the base of the tree indicate active internal decay
Deep cracks in the bark or visible splits in the trunk signify the outer shell of living wood is failing under the tree's weight
A sudden lean or mounded soil raising on one side of the root system indicates the tree's foundation is unstable, and it is at risk of falling
Thinning leaves, dropping branches, or dieback at the crown of the tree can show that the tree's sapwood is dying
And finally, a tree with a hollow located near structures poses a higher immediate risk than one located on the outskirts of a property
What to do Next
If you have concerns about a hollow tree in your yard, please don’t hesitate to contact us at Gregory Forrest Lester, Inc. One of our certified arborists can assess the tree to determine whether it needs to be removed, pruned, or if it is structurally sound. Our arborists can also implement support systems, such as cables or braces, to help stabilize trees that show initial signs of instability. While hollow trees are not always dangerous and can provide significant benefits to local wildlife, it is important to evaluate the potential risk they may pose to you and your property. If you feel a hollow tree poses a danger, reach out to us at Gregory Forrest Lester, Inc.