Rhododendrons have a compact, shallow root mass. The entire system on this 10-foot high plant was less that a foot deep. Notice how flattened the tap root is. The branching roots grow slightly upward from there, giving the root ball its typical rhododendron saucer shape. It is easy to see why rhododendrons benefit so much from mulch to keep the roots moist and cool.

A winter windstorm uprooted this rhododendron and it never recovered. I used a pressure washer to remove the dirt while leaving even the hairline roots intact.