Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Black Walnut > Large woody growth on trunk
Black Walnut > Trunk/Branches > Large woody growth on trunk
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Burls
- Large round to semi-circular swellings along main trunk or large branches
- Many buds of sprouts may be present on the exterior of the burl
- Common on sugar and Norway maples
- Burls continue to grow as the tree grows
- While burls do not kill trees directly they can reduce a tree's health and lifespan
- There is no known cause for burls
- More information on Burls
