This weeping shrub, native to China, needs full sun to partial shade and moderate moisture conditions to reach a height of 15 feet. In May to June it produces showy lilac-purple blooms that attract butterflies. The drooping spikes can be 12-15 inches long. This butterfly bush grows much larger than the common davidii cultivars and is less likely to die back during winter. Because it blooms on old wood, it should only be pruned after flowering. It can be used as a specimen or as a barrier planting because its size.