Tree
Girdling root
A girdling root is a root that wraps around the trunk or other roots, usually at or below ground level, and can slowly squeeze and choke the tree.
A girdling root circles the trunk instead of growing outward. Penn State Extension defines it as a root that grows to encircle a tree trunk, usually at ground level or below the soil line.
It starts small and is easy to ignore. Penn State says that as a girdling root grows, it gradually chokes the sap flow from delivering food through the trunk phloem to the roots below. Over time the trunk can weaken where the root binds it.
Girdling roots matter on a living tree, not on a stump. A cut stump has no sap flow to choke. They relate to planting too deep and tight root balls, and a certified arborist can judge whether to cut one. On a stump job, girdling roots near the root flare are removed along with the stump if the grinder reaches them.