Cavity in trunk of tree - Ask Extension
We moved into our current house in the autumn of 2018. At the time the tree in the photo (it seems to be some type of miniature maple tree) exhibited...
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Cavity in trunk of tree #845293
Asked August 11, 2023, 4:08 PM EDT
We moved into our current house in the autumn of 2018. At the time the tree in the photo (it seems to be some type of miniature maple tree) exhibited damage apparently from losing a branch. The damage created a cavity about four inches deep which generally is wet at the bottom. Since 2018 we have been busy with house repairs and home improvement. I am finally writing to ask what to do with the cavity. In spite of the damage, the tree seems to be thriving. Should I leave it alone? Should I fill the cavity with something? If so, what would be an appropriate filler?
Oakland County Michigan
Expert Response
Hello,
Arborists and tree experts no longer recommend filling cavities in trees. Doing so creates more problems- it interferes with the tree's natural "healing" process. This is because filling materials do not bond with the rotted wood in the hole, and hold the moisture in place-rather than allowing for drying.
I would recommend pulling some of the mulch away from the base of the tree trunk for starters, and trying to find the root flare (the widening of the trunk above the root system). If the tree seems healthy otherwise, it may be that it was able to contain the rot and will live for more years to come.
It is important to treat this tree as you would a "stressed" tree, in that you want to make sure it is getting sufficient water, and taking care not to over-fertilize, which can stress a tree. If you decide you want to have someone who can look at the tree on site, we always recommend consulting an ISA-certified arborist from the following website:
https://www.treesaregood.org/findanarborist
This looks like a Japanese maple, by the way.
I hope this is helpful.
Thank you for contacting Ask Extension.
Ruth
Arborists and tree experts no longer recommend filling cavities in trees. Doing so creates more problems- it interferes with the tree's natural "healing" process. This is because filling materials do not bond with the rotted wood in the hole, and hold the moisture in place-rather than allowing for drying.
I would recommend pulling some of the mulch away from the base of the tree trunk for starters, and trying to find the root flare (the widening of the trunk above the root system). If the tree seems healthy otherwise, it may be that it was able to contain the rot and will live for more years to come.
It is important to treat this tree as you would a "stressed" tree, in that you want to make sure it is getting sufficient water, and taking care not to over-fertilize, which can stress a tree. If you decide you want to have someone who can look at the tree on site, we always recommend consulting an ISA-certified arborist from the following website:
https://www.treesaregood.org/findanarborist
This looks like a Japanese maple, by the way.
I hope this is helpful.
Thank you for contacting Ask Extension.
Ruth
Ruth, Very clear explanation. I am pleased that my inaction was not detrimental. Thanks for your help.
