Table 3.

Effect of planting depth in the nursery container and root pruning at landscape planting on root growth 68 months later.

Depth into 11, 57, and 170 L nursery containerz (mm)Root pruningyTotal CSA roots >10 mm diameter growing up >20 degree angle outside 170 L container root ball (mm2)
13/ 0/ 0None866 bx
Shaved706 b
13/ 64/ 0None847 b
Shaved738 b
64/ 0/ 0None696 b
Shaved909 b
64/ 64/ 0None525 b
Shaved1517 a
  • z Point where the topmost root emerged from trunk planted at indicated distance below substrate surface into three container sizes; 20 cm tall liners in square propagation containers originally planted into 11 L nursery containers.

  • y Root pruning removed (shaved) the outer 3 cm of the 170 L root ball periphery prior to planting into landscape soil.

  • x Numbers followed by a different letter within columns are statistically different at P < 0.05; n = 6, averaged over landscape planting depth due to insignificant interaction with landscape planting depth (P = 0.25).