This is what Greenleaf Nursery says about this particular Buddleja:
"Like the rest of its tribe, Asian Moon Buddleia is a fast-growing deciduous shrub that will require some pruning to keep it fresh each spring. It is best kept within bounds by coppicing or cutting to the ground in late winter, while in late July cutting the shrub back by half will control size and encourage heavy reblooming. Also like other members of the genus, Asian Moon is nearly indestructible, adaptable to gardens from Boston to Florida (U.S.DA. Zones 5-9). Consider Asian Moon Butterfly Bush as an easy-care selection that provides plenty of garden color and fragrance in full sun.
Useful in the landscape for summer bloom and to attract butterflies; used in masses, not as a specimen; can be treated as a herbaceous perennial to give height in the mixed border; or under-planted with low perennials."
