Effect of Container Type and Root Pruning on Growth and Anchorage After Planting Acer rubrum L. into Landscape Soil

Acer rubrum L. ‘Florida Flame’ were grown in #3 containers of eight types, then shifted to #15 containers, then finally into #45 containers. Half the trees were root pruned by removing periphery 3 cm of root ball at each shift to larger containers. In addition to and simultaneous with being shifted into successively larger containers, some trees from each container size were planted directly into soil. Type of container and root pruning had no impact on trunk diameter, tree height, or root cross-sectional area on trees planted into soil from any container size. Type of container influenced architecture of planted root systems evaluated when all trees were five-years-old with limited impact on anchorage. Container type only impacted anchorage of trees planted from #45 containers, and impact was small. In contrast, shaving root balls during production substantially reduced imprint left by all containers evaluated when trees were five-years-old. Shaving during production also improved anchorage by 20%–25% compared to not root pruning. More roots grew on north than the south side of tree in the nursery and landscape. Bending stress increased with trunk angle and its square while winching trunks to five degrees tilt.