"Root-bound" is the condition of a plant or tree that has outgrown its confinement. It can happen to the smallest seedling in a pot or the largest tree in a back yard, as in their search for nutrients, the roots will explore every nook and niche. Before planting, It is common practice to make vertical cuts with a knife through this wall of roots to encourage new outward root growth.

They may follow the path of least resistance during normal growth, or follow traces of nutrients when they are undernourished. Trees have been known to lift sidewalks, totally clog steel pipes, and go through house foundations in their quest for water and nutrients.

There is a similar condition called "Girdling" where the roots encircle the lower tree trunk, and can exert enough force to stop the normal flow of sap. The Strangler Fig Vine routinely exercises this Girdling condition on its victims as it climbs to the tops of trees for sunlight, where it creates its own canopy keeping sunlight from reaching lower vegetation.