The highest-quality root balls have the point where the top-most root emerges from the trunk within 2 inches of the surface as shown at left. Poorer-quality root balls have the the top-most root and root flare (if present) buried down inside the root ball as shown at right. A close look at the two root systems above will show that trees with the top-most root too deep in the ball have less of a root system than trees with the top-most root near the surface. As the distance between the top-most root and the soil surface increases, the percentage of the root system harvested from the field nursery decreases.