If you allow your wax myrtle to grow unshorn, it will reward you and the native songbirds with multitudes of gun-metal blue bayberries. The berries, leaves, twigs, and trunks of the wax myrtle are aromatic. Certain songbirds relish the fruit, which will be greatly diminished or nonexistent if your plants are sheared too much.

Years ago, we planted slash pines along the highway right-of-way in front of our house and, then, underplanted the pines with wax myrtles. Over time, this planting has elminated the need for lawn maintenance. Also, over time, the wax myrtle has been sheared at least twice a year by the county road crew, which, as everyone knows, has the well-deserved reputation of being horticultural butchers. But to make a long story short, their wax myrtle butchery has been a good thing. Their chopping has kept the wax myrtle that's within their reach at a low, densely-foliaged height and has encouraged it to colonize, which is another of its natural tendencies. Wax myrtle is particularly attractive in the winter when its evergreen foliage shines in the sun.

If you continue to prune them only at the top, you'll never see them fill out at the bottom, as I believe you are wanting. You'll need to perform a proper rejuvenation cut, best accomplished in the late winter/early spring. Cut the shrubs to 6 inch stumps or less at that time. You'll probably see three or four feet of growth that first season.

From then on, you'll need to prune it properly so that new growth continues to be generated all up and down the trunks.