Girdling roots are roots that grow in a circular or spiral pattern around the trunk, gradually strangling it. As these roots encircle the trunk, they impede the flow of sap within the tree. This obstruction prevents the movement of carbohydrates produced by the leaves through photosynthesis, resulting in an inadequate supply of nutrients to the roots. Girdling roots commonly form in root-bound container-grown plants, but they can also develop as trees mature, especially in red and sugar maples, 'Greenspire' lindens, American beech, pines, oaks, poplars, zelkovas, and elms.
Recognizing the symptoms of girdling roots is crucial in addressing the issue promptly. Look out for the following signs:
Reduced sap flow resulting from girdling roots makes the tree more susceptible to insect infestations, diseases, and environmental stress.
While treatment for girdling roots is theoretically possible in very young trees by excavating and trimming the girdling roots, it is often challenging to address the issue once symptoms become evident. In many cases, the roots have already fused together to the point where cutting them would cause further harm to the tree.