Trees growing in urban spaces such as streets, parking lots, commercial and other areas usually do not have enough space for their roots. Building foundations, curbs, retention walls, containers and paving can all restrict the full growth of a tree's root s.
Trees exist in the spaces left over after other infrastructure is in place.
Often they are planted in containers and median strips. 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.