Trees growing in such spaces are more subject to girdling roots, drought effect, and other secondary problems such us pests and disease. Often this problem is related to compacted soil condition or soil erosion or is a result of heavy use of the space close to the tree. Girdling Roots T he normal pattern of tree root growth is horizontal to the ground surface and radially away from the trunk. The pattern of girdling roots is to grow tangentially to the trunk, and in many cases, upwardly. Figure 1 Girdling root symptoms are found more often on park, street, yard, and trees in nursery trees than on forest trees.
Many symptoms can indicate girdling roots.
These include weak foliage and defoliation. Trees with a root that girdles the lower trunk usually have little or no flare on one side of the tree at the ground line. You should keep in mind that if soil is spread around a tree, the butt flare may also be buried. In this case, the effect will be the same all around the tree.