10/02/2026
š³ WHY DONāT WE FILL HOLLOW TREES WITH CONCRETE ANYMORE? š§
If you have an old tree with a big hollow spot or cavity, you may have heard someone say:
š āJust fill it with concrete!ā
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 todayāand it turns out that concrete doesnāt āhealā or restore a damaged tree. š³
In some situations, filling a cavity with concrete can actually create additional problems by:
š§ Trapping moisture
š¦ Encouraging decay around the filled area
š”ļø Expanding and contracting differently than the wood
ā ļø Creating additional stress as the tree moves in the wind
š Making it harder to properly inspect what is happening inside the trunk
And hereās something many homeowners donāt realize:
A hollow tree isnāt automatically an unsafe tree!
Trees have an amazing ability to compartmentalize decay and continue growing strong wood around damaged areas. Thatās why simply seeing a cavity doesnāt tell us whether a tree is safe or dangerous.
š³ Modern tree care looks at the whole treeānot just the hole.
We look at the amount of sound wood remaining, the location and extent of decay, the treeās structure, surrounding targets, and how the tree could respond to wind and storms.
So the next time someone says, āJust fill it with concrete,ā remember:
The goal isnāt to hide the problem. The goal is to understand the tree.
š² 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 trimmingā¦your turn. Drop a picture in the comments! ššø