Crape myrtles (Lagerstroemia spp.) are woody shrubs or small trees prized for their long blooming period. The plants feature showy panicles of colorful flowers that persist throughout the summer months. Crape myrtles are also desirable for their general hardiness -- they can tolerate urban conditions and are drought-tolerant. Although species and cultivars vary widely in size, they all grow rather quickly.
Crape myrtles grow rapidly. The most common species grown in America, Lagerstroemia indica, grows at a fast rate, as does L. speciosa and L. fauriei. A fast rate of growth is defined as 25 inches or more per year, according to the Arbor Day Foundation website. This means that most crape myrtles, if cared for properly, will grow at least 2 feet per year.
Some trees that grow quickly do not establish well. They also tend to be weak and suffer from insect pests and diseases. Fortunately, crape myrtles do not have such problems. It only takes two years for a crape myrtle to become well established, according to the Clemson Cooperative University website. These plants quickly develop a strong and healthy root system in optimum conditions, and rarely suffer from diseases, although they can be bothered by aphids and scale.
Some cultivars reach maturity much faster than others. Although all grow at about the same rate, some are much smaller in form than their counterparts. Acoma, for example, is a white-flowering cultivar of L. indica that grows to a maximum height of around 10 feet. Balsam's Party Pink, on the other hand, is another variety of L. indica that can grow up to 50 feet tall. Caddo may be as small as 5 feet in size, but it more than makes up for a lack of height with very bright pink flowers. Lagerstroemia speciosa is not a cold-hardy crepe myrtle, as it only grows well in U.S. Department of Agriculture zones 10 and 11, but it is massive in size -- ranging from 40 to 60 feet in height, with a width of around 35 feet.
The growth of crape myrtles will suffer if they are not cared for properly. Adverse environmental conditions can slow or stunt the growth of the plants. The most important requirement of crepe myrtles is their need for full sun -- without a good amount of light, they will not bloom properly or prolifically. The plants grow well in all types of soil as long as it is well draining, but they are not tolerant of salt in the soil or in the air. Some species and cultivars are not frost-tolerant.