A butterfly bush unlike any other! Mop Top is a dwarf spring-flowering butterfly bush that brings elegance and whimsy to the garden, and its spring flowers are perfectly timed to captivate gardeners during the prime garden center shopping season. Known as fountain butterfly bush, this Buddleia alternifolia selection lives up to its name with long, slender, weeping branches that are covered in lavender flowers in spring. Mop Top butterfly bush is a hardy down to USDA zone 4, a whole zone hardier than Buddleia davidii selections.