The White Butterfly bush, Buddleia davidii 'Alba', is easily grown in average, medium wet, well-drained soil in full sun. This deciduous bush becomes weedy and sparse with diminished flowering performance if not grown in full sun. Does poorly in wet conditions.
In USDA Zones 5 and 6, this plant will often die to the ground in winter and therefore is often grown in the manner of an herbaceous perennial. Even if plants do not die to the ground in winter, they usually grow more vigorously, produce superior flowers and maintain a better shape if cut to the ground in late winter each year. Removal of spent flower spikes during the growing season will encourage additional bloom, but consider leaving final blooms in place to facilitate reseeding.