Article: Scoop out the loose soil on the site you tilled previously. The hole should be approximately the same depth as the nursery pot holding the plant. It’s not a good idea to seat the root ball any deeper, as the soil around it needs to stay oxygenated.  If necessary, measure the height of the nursery pot before digging the hole. The top of the root ball should be just about level with the uppermost layer of soil. Because of their intensive germination requirements, crepe myrtles headed for home gardens are almost always grown from saplings.

What is a summary?
Dig a hole roughly three times as wide as the root ball.