10/02/2026
🌳 WHY DON’T WE FILL HOLLOW TREES WITH CONCRETE ANYMORE? 🧐
If you have an old tree with a big hollow spot or cavity, you may have heard someone say:
👉 “Just fill it with concrete!”
Believe it or not, that really was a common tree-care practice years ago. The idea was that concrete would fill the empty space and make the tree stronger.
But we know much more about tree biology today—and it turns out that concrete doesn’t “heal” or restore a damaged tree. 🌳
In some situations, filling a cavity with concrete can actually create additional problems by:
💧 Trapping moisture
🦠 Encouraging decay around the filled area
🌡️ Expanding and contracting differently than the wood
⚠️ Creating additional stress as the tree moves in the wind
🔎 Making it harder to properly inspect what is happening inside the trunk
And here’s something many homeowners don’t realize:
A hollow tree isn’t automatically an unsafe tree!
Trees have an amazing ability to compartmentalize decay and continue growing strong wood around damaged areas. That’s why simply seeing a cavity doesn’t tell us whether a tree is safe or dangerous.
🌳 Modern tree care looks at the whole tree—not just the hole.
We look at the amount of sound wood remaining, the location and extent of decay, the tree’s structure, surrounding targets, and how the tree could respond to wind and storms.
So the next time someone says, “Just fill it with concrete,” remember:
The goal isn’t to hide the problem. The goal is to understand the tree.
🌲 Wicked Nature LLC Tree Service
When nature gets wicked, we get to work.
Have you ever seen a tree that was filled with concrete? Here is a picture of a recent tree trimming…your turn. Drop a picture in the comments! 👇📸
