This is the average expected mature height by width in feet or inches. Feet are represented by a single quote and inches by a double quote. Under poor growing conditions plants may be slightly to significantly smaller, whereas excellent growing conditions can produce larger more vigorous plants. USDA Cold Hardiness Zones were established to give gardeners, horticulturists, farmers, nurseries, and landscape architects a universal way to describe where a plant will survive with regard to average winter lows for a region. And these are averages, here in zone 8B 'A' represents the colder half of a zone and 'B' represents the warmer half of the zone and they are separated by about 5 o F we have seen single digits but that is the exception but should be noted by the daring gardener.
Crepe Myrtle (Lagerstroemia 'Ebony and Ivory') in the Crepe Myrtles Database - opinion24.info
Growzone: White flowering Ebony and Ivory Crape Myrtle is an exciting new Crape Myrtle hybrid that has the darkest black leaves anyone has seen on any Crape Myrtle, or any other shrub or tree for that matter! Ebony and Ivory Crape Myrtle blooms in early summer with pure white flowers. It forms a small tree, with a dense, full shape. The foliage is a true black that contrasts well with the bright white flowers.