Happy Arbor Day , I Know a Tree , A Tree's True Color , Leaf Printing or the activity, Trees and Air Quality Procedures Dig a wide hole. The diameter of the hole should be at least 2 and preferably 3 or more times the diameter of the root ball. The hole should be shaped like a shallow bowl, not a vertical column.
Roots grow primarily near the surface.
Loosening the soil as far as possible away from the trunk will make it easier for the roots to grow and establish. Don't plant too deep. Leave the soil beneath the root ball undisturbed. The hole should be dug only as deep as the root system otherwise the ball will settle and the root collar will be too deep. Use existing soil to backfill.