Powdery Mildew is a fungal disease of crape myrtles in McDonough, Georgia.  This type of disease most often occurs during the spring but may occur at any point during the growing season.  The development of powdery mildew is favored by warm days followed by cool nights.  Extended periods of dry weather and excessive shade also promote development of disease.  This type of disease produces very distinct white patches of fungus on the plant leaves.  The fungus often stunts the growth of new foliage, the leaves and shoots.  Affected plant leaves may also drop early from the tree.  However, the disease is not usually detrimental to the tree itself.  To avoid powdery mildew on your crape myrtles in McDonough, Georgia, it is important to promote a healthy growing environment for your trees.  Place your crape myrtles in areas of full sun with adequate space between trees, making sure the trees are NOT touching.  This will promote better air flow between trees.  In severe cases of powdery mildew a fungicide may be needed to control the disease.