As arborists in Atlanta, we are often asked “Why do Bradford Pear trees split?” The simple answer….. included bark.
Included bark is basically bark that gets trapped in between the trunk and a branch specifically where the union between the two is very narrow.
Most trees have a fairly wide branch attachment angle, however, Bradford pears have a very narrow angle. As the branch and trunk grow in width, due to this narrow angle, they begin to “smoosh” (for lack of a better term) into each other.
The more they grow together, the more bark is “included” in the union. The problem is that there is no connecting or horizontal fiber to add structural stability to the tree. The lack of horizontal fiber on the top side of the branch means that the tree is unable to create “reaction growth” which adds strength to the tree. Reaction growth can be formed at the base of the branch, but because of the included bark, not at the top.
This weakened structure cause Bradford pears split and worse, at inopportune times crossing driveways or perhaps streets.
Asset or liability?
Ultimately, most arborists view Bradford pears as liability to the property and not an asset. Specifically because of their weak structure, they typically cause frustration and lots of money to clean up.
If you’re considering planting new trees, it may be wiser to consider some species other than Bradford pears.