The beautiful tubular, nectar-rich flowers (6 to 24" panicles) of this bush have a wonderful scent! They come in a variety of colors....purple, light blue, lavender, reddish-lavender, pink, white, or golden-yellow. The foliage is gray green to blue green with a white underside and emerges late in spring.
They can get to be quite large, up to 8' tall and 8' wide....smaller in the north 5'x 5'.... and are fast growers. They can be invasive, especially in the wet areas of the Northwest U.S.
They like a position with full sun, if possible and are fairly forgiving surviving heat, drought and high humidity.
Buddleia blooms from July through frost and beyond in warmer climates. Deadhead (remove the flowers) for best flowering.
The hardiness zone for Buddleia is zone 5 - 11 and it can survive year-round in zones 9-11. I have tried growing butterfly bush in my zone 4 garden, but haven't had much luck with it surviving very long.
Butterfly Bush Pruning
Pruning of Buddleia should take place in late winter or early spring. Cut down close to the ground, removing all dead branches and cut above shoots if there are any visible. Flowers are on new growth, so even in zones 9-11 it is a good idea to cut them once a year.
Varieties or Cultivars of Buddleia davidii
Buddleia davidii Royal Red - one of the best varieties, heavy flowering, intense deep color
Buddleia davidii Black Knight - dark purple, almost black flowers
Buddleia davidii Pink Delight - more compact plant (4-6') with deep pink flowers
Honeycomb - also called summer lilac, has yellow flowers
More varieties include Peacock, White, Blue and Bi- color
Buddleia alternifolia - unusual, up to 12' tall, large lavender flower spikes bloom in the spring, pruning Buddleia alternifolia is done after blooming not in late winter like the rest of the cultivars...it blooms on previous season's growth