Summer in Texas would not be complete without the abundance of crape myrtle flowers now beginning to be conspicuous over most of the state. Proper fertilization and pruning usually result in a long display of flowers of three months or more.
Fertilizer recommendations are best made after reviewing soil test results, but a general recommendation of 2 pounds of nitrogen per 1,000 square feet of root area is sufficient for most trees and shrubs. This can be repeated again in the late fall. The first application should be made just before new growth begins in the spring. The number of square feet in the root area is determined by the branch spread of the tree.
The most significant disease affecting crape myrtle is powdery mildew. This can be controlled by spraying with Benomyl or Funginex, used according to label instructions. Mildew is usually less of a problem if plants are located in open sunny areas where air circulation is good.
Pruning is best done in late winter before new growth begins. The structure and trunks of crape myrtle are among their chief assets; therefore, pruning should normally involve only removing dead and twiggy growth to expose the sculptural character of the tree.
For dwarf varieties or in shrub borders where crape myrtles may be grown only for their blooms, severe pruning will help insure larger and more prolific flowers. The pruning of faded and seedy blossom heads will usually promote repeat blooming late in the summer.
For something different, try some of the dwarf type crape myrtles in tubs or pots on the terrace. They do best in sunny areas, and are as satisfactory for container use as they are in the ground. By Dr. William C. Welch, Landscape Horticulturist
Texas A&M University, College Station, Texas