Effect of landscape planting depth on magnolia growth and anchorage.
| Landscape planting depthz | Tree height increase 2012y (m) | Root system radius eight months after plantingx (cm) | Root:shoot eight months after plantingw | Depth to root collarv (mm) | |
|---|---|---|---|---|---|
| 5 cm high | 2.5 br | 76 a | 0.71 a | 22 b | |
| 10 cm deep | 2.7 a | 59 b | 0.56 b | 156 a | |
| Landscape planting depth | Percent trunk with tangent/circling roots (>10 mm diameter) within 170 Lu | Total CSA roots growing up >20 degree angle outside 170 L container root ball (mm2) | Hinge point at five degrees trunk pullt (cm) | Rest angle after winchings (degrees) | |
| 5 cm high | 66 a | 380 b | 18 a | 1.1 a | |
| 10 cm deep | 43 b | 972 a | 12 b | 0.8 b | |
↵z Root collar installed 5 cm above or 10 cm below landscape soil surface.
↵y Not significant (P > 0.10) for the years 2009–2011; trees installed September 2008.
↵x Distance between the edge of the planted 170 L root ball and the tip of the farthest root measured on the east and west side of tree.
↵w Ratio of distance between trunk and root tips to trunk and branch tips to the east and west.
↵v Distance between top of mulch and root collar.
↵u Percent of trunk circumference with roots growing tangent to or circling trunk that touched or were embedded into the bark.
↵t Distance between trunk and the point where root plate dipped to its lowest point at five degrees tilt.
↵s Trunk angle relative to vertical start position after winch is released following five degree trunk tilt 68 months after planting.
↵r Numbers followed by a different letter within columns are statistically different at P < 0.05; n = 24, averaged across planting depth in nursery container and root pruning due to insignificant interactions (P > 0.19 and 0.16, respectively) with depth in the landscape.