Large shrubs can often be trimmed into tree-like forms, with one or more main trunks. Although the process is easier with smaller 1-year-old shrubs, it can also be done on older, mature shrubs. Trimming should be done in late winter or early spring before new growth appears. Crepe myrtles, evergreen viburnums, wax-leaf ligustrums and yaupon hollies are easy to trim into trees.
Remove small limbs up to ½ inch in diameter with hand pruners, and lopping shears for larger branches. Cut limbs and branches at a 30-degree angle just below a node, or just above a joint.
Trim upright branches at ground level with hand pruners or lopping shears after choosing one to three vigorous branches for the trunk or trunks.
Trim lateral (horizontal) limbs and branches from the main trunk or trunks with hand pruners or lopping shears. Remove all limbs and branches up to 4 feet high.
Prune out dead, diseased or damaged limbs and branches. Symptoms of diseases include cankers or lesions on limbs or branches, dead or dying foliage, and discolored foliage.
Thin the canopy of the tree with hand pruners or lopping shears by removing inward-growing branches and crossed branches. Trim elongated or wayward-growing branches that spoil the shape of the canopy. Step back often to view the shape of the canopy while you are working.
Remove any suckers that grow on the trunk or trunks in the following years, using hand pruners or your fingers. Maintain the shape of the tree canopy with annual trimming.