A comment I often get is that people have a plant too large for its space.
Trees, shrubs and even ornamental grasses can outgrow the area they are in.
One of the ornamental grasses that can quickly outgrow its area is pampas grass, a large perennial grass native to Brazil, Argentina and Chile. It grows in clumps 8 to 10 feet tall and 6 to 7 feet around. In late summer, it will produce silvery-white or pinkish silken plumes which rise to a height of 12 feet.