Hello DeAnna,

Black Locust (Robinia pseudoacacia), is a fast-growing tree which colonizes areas. Read more about it here: https://extension.umn.edu/identify-invasive-species/black-locust

There are many causes of bark cracking in trees including environmental factors such as sunscald or frost cracking which usually occur on the south west side of the tree.

Girdling roots could also lead to cracking of bark. This occurs when the roots tighten around the tree, damaging the cells and choking off the movement of nutrients and water into the tree. They can also weaken or compress the trunk of the tree above the root collar flare which may be happening here and causing the bark to crack due to the pressure. Read more here: https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/environmental/girdling.aspx

Cracks can also be caused by included bark which may be happening in this tree where the limb connects to the tree trunk. Bark inclusions can cause cracked trunks and damaged trees. Branches with no inclusions, such as those attached to the trunk at a 90-degree angle are stronger than those that have a “V” Shaped union. Branches or codominant trunks that have a “V” shaped union are weak. As the tree grows and puts on girth, the trunks push against each other and cracks develop in the bark. This will lead to failure of the tree.

I’m attaching an article from the University of Florida which discusses how to prevent these problems in detail. https://hort.ifas.ufl.edu/woody/documents/ch_12_mw04.pdf

It is difficult to diagnose the problem from pictures. A certified arborist will be able to assess your tree. To find an arborist in your area, go to www.treesaregood.org , the website of the International Society of Arboriculture.

Thank you for contacting Ask Extension.