Southern wax myrtle, or Myrica cerifera, is a tree that grows in U.S. Department of Agriculture hardiness zones 7 to 11. Achieving heights of 15 to 25 feet, the plant grows fast in a vaselike or rounded shape. Wax myrtle is low maintenance and it can grow in flooding, drought and salt conditions. It's often used in borders, along shorelines, as a screen or to help prevent eroding. The tree often grows with several trunks, and has thin branches and twigs. Prune the wax myrtle to shape the tree, remove diseased wood and improve air circulation.
Remove sprouts growing along the base of the wax myrtle in the summer. The tree tends to grow sprouts from the roots. These "suckers" are stealing nutrients and water from the tree and make the planting look messy. Prune the sprouts by cutting them where they meet the tree trunk or ground. This will prevent regrowth.
Look through the tree's canopy. Branches that are crossing or rubbing each other should be removed because they are preventing good air flow to other branches. Cut them where they need other branches, making a clean cut without tearing the branches.
Trim lower branches to keep the diameter small. Removing large branches opens the tree up to canker fungi and decay. The fungi enters through wounds such as pruning cuts, making the tree die sooner.
Eliminate dead, diseased or weak branches. Wax myrtle is prone to splitting in snow and ice. Cut them off at the point where they meet healthy wood.