A girdling root is one that grows in a circle (rather than a linear route outward) around the trunk of the tree, either at ground level or just below the surface. If it is too close to the trunk it can interfere with the supply of water and nutrients. Girdling roots are more likely to occur in maple (except silver maple), magnolia, linden, pine and ash trees.
Girdling of roots is common with container grown trees because the roots have no place to grow other than in circles. A ball and burlap tree probably will not have this problem because the roots are cut when it is transplanted. Trees in small pits in urban areas are likely to have girdled roots because they do not have room to spread.
Unless the girdling root is visible you will have to go by certain signs to determine if you have one or more. For example, when a tree has a girdling root on one side, it may |  Girdling Roots
not have a flare on that side, the leaves may be smaller or the leaves may change color earlier than the rest of the tree. Sooner or later, the branches die. If the tree is girdled on all sides, the whole tree may die or blow over in high winds because it does not have firm linear roots. |