Split in a sugar maple tree (25 years old) - Ask Extension
This spring we noticed a split down the two main branches that feed into the trunk of our sugar maple tree has split. We do not want to lose this tre...
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Split in a sugar maple tree (25 years old) #930339
Asked May 01, 2026, 8:29 PM EDT
This spring we noticed a split down the two main branches that feed into the trunk of our sugar maple tree has split. We do not want to lose this tree. What can be done to save it? What causes these cracks?
Sherburne County Minnesota
Expert Response
Thank you for writing.
When I saw the message, I first assumed it was a sap thaw freeze crack. Exploding trees are real and we had a great spring for it with a good thaw, running sap and a cold freeze. facebook.com/reel/<personal data hidden>54279/
You have a different problem. You have large branches at a very acute angle. Eventually the weight of the branches and the wind opens up a crack at the top of the angle water and fungus gets in (that black stuff), the core of the tree weakens and the tree splits. Maples need regular pruning to prevent this. The tree may be dying and is certainly structurally unstable. An arborist (see my signature line) should be consulted for pruning if possible, removal if necessary.
See fig 7 chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.extension.purdue.edu/extmedia/FNR/FNR-614-W.pdf
https://www.dnr.state.mn.us/treecare/maintenance/prevention.html
Sorry
When I saw the message, I first assumed it was a sap thaw freeze crack. Exploding trees are real and we had a great spring for it with a good thaw, running sap and a cold freeze. facebook.com/reel/<personal data hidden>54279/
You have a different problem. You have large branches at a very acute angle. Eventually the weight of the branches and the wind opens up a crack at the top of the angle water and fungus gets in (that black stuff), the core of the tree weakens and the tree splits. Maples need regular pruning to prevent this. The tree may be dying and is certainly structurally unstable. An arborist (see my signature line) should be consulted for pruning if possible, removal if necessary.
See fig 7 chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.extension.purdue.edu/extmedia/FNR/FNR-614-W.pdf
https://www.dnr.state.mn.us/treecare/maintenance/prevention.html
Sorry
