Growth Response of Crapemyrtle to Production Light Level and Supplemental Fertilizer

The effects of production light level on growth of crapemyrtle were evaluated as a means of accelerating the development of tree-form crapemyrtles (Lagerstroemia spp.). By the end of the first growing season, plant height and shoot length of ‘Fantasy’ and ‘Tuscarora’ were greater when grown under 50 or 80% shade than when grown in full sun. By the end of the second growing season, height and shoot length of all three cultivars grown under one or both shade levels were greater than those of plants grown in full sun. In a second experiment, ‘Carolina Beauty’ and ‘Tuscarora’, but not Dynamite™, were taller at the end of the first growing season when grown under 50 or 80% shade than when grown in full sun. Flowering of all cultivars grown under shade was suppressed or delayed. Caliper of Dynamite™ and ‘Tuscarora’ at the end of the first growing season was greatest when grown in full sun, while production light level had no effect on caliper of ‘Carolina Beauty’. At the end of the second season, during which all plants were grown in full sun, there were no height, caliper, or flowering differences of any cultivar due to previous production light level, except for less caliper growth of ‘Tuscarora’ previously under 80% shade compared to plants grown in full sun.