Butterfly bush likes well drained, average soil. They thrive in fairly dry conditions once established. Roots may perish in wet soil. Butterfly bushes are semi-evergreen in climates with mild winters. They may be cut back to the ground and will re-emerge from roots in their northernmost range, but will not reach the maximum size they do in warmer climes. It is advisable to cut back the shrubs in any case, since flowers are usually larger and more prolific on new wood.
Similar species -Buddleja madagascariensis.