Home > Urban/suburban design > Street tree design > Canopy habit and form > Rounded
Rounded growth form
 Without structural pruning, decurrent trees can break apart. |
Because fewer branches droop on young rounded, or spreading, trees (decurrent growth habit) than on pyramidal trees, this type of tree might not be pruned in the first 10 years after planting, because there may be few complaints from citizens about drooping branches.
However, without some pruning, tree structure may deteriorate due to weak branch attachments (see below). During this 10 year period, trees can develop several aggressive, upright trunks, some with weak included bark in the crotches. This could lead to breakage in storms as trees grow (see below).
Therefore, preventive pruning to develop good structure when trees are young is recommended on all trees, especially those with a rounded canopy shape. Pruning at two, five, and ten years should be considered a minimum requirement. Pruning at one, three, five, and ten years would be even better.
