In addition to being an attractive design element, a stone border circling a tree is quite a practical structure in several different ways. It protects the tree trunk from contact with lawn mowers and edge trimmers. It also corrals mulch from spreading to the lawn.
Depending on the height of the border and the material used, a tree ring can also provide a pleasant seating area. As long as a tree ring is installed with the tree’s health in mind, it is overall a very good landscaping idea.