The butterfly bush (Buddleia davidii) is a beautiful, fast-growing, deciduous shrub with masses of blossoms—long, spiked trusses—that bloom from summer to autumn.
Its flowers come in many colors, though butterflies seem to prefer the lavender-pink (mauve) of the species to the white and dark purple cultivars.
Also called “summer lilacs,” butterfly bushes are hardy to Zone 5 and remain evergreen from Zone 8 south. The shrub is low-maintenance, only requiring dead-heading and annual pruning in later winter to encourage flowers and a compact shape.
Please note that the butterfly bush, originally imported from China, is now being classified as an invasive species in most U.S. regions, which means it’s crowding out native plants that are essential to wildlife, including butterflies and birds. In warm climates, it can become a noxious weed and spread aggressively. In cooler climates, it seems content to stay contained within a garden’s cultivated soil if gardeners deadhead the flowers.
Also, despite the “butterfly” name, keep in mind that this shrub is not a “host plant” for butterflies in that it does not support butterfly reproduction and lifecycle. Rather, it provides nectar to adult butterflies; think of nectar as their favorite adult beverage! If you do have a butterfly bush, be sure to add native host plants such as milkweed if you want the butterflies to stay. See plants that attract butterflies.
There are non-invasive American butterfly bushes. Please check with your local cooperative extension for more information.