Flower clusters of butterfly bush (Buddleja davidii).
Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Updated: January 28, 2026
Butterfly bush (Buddleja davidii, also sometimes spelled Buddleia) is a deciduous flowering shrub native to Asia, introduced around 1900. There are several species and hybrids of Buddleja in U.S. horticulture, but cultivars derived from B. davidii are the most commonly grown.
The attractiveness of the blooms to pollinators like butterflies is what gives the plant its common name, though it may also occasionally be called "summer lilac" (despite having no relation to lilacs in the genus Syringa) due to the summer bloom period and fragrant flowers.
Physical features of butterfly bush
Dozens of butterfly bush cultivars have been developed in recent decades; they vary in flower color (and to a lesser degree, in leaf color) as well as in mature size. The shrub is deciduous, shedding leaves in autumn; the leaves turn yellow or don't develop much of a color change.
The very long bloom season (from midsummer until mid-autumn), fragrance, ease of cultivation, and butterfly draw are the main appeal for gardeners. Deer generally do not browse it.
Growth rate and habit: dwarf varieties mature wider than tall; mid-size varieties are rounded; full-size varieties mature taller than wide, with arching branches; rapid growth rate (several feet per year, even if cut back in spring), except for dwarf varieties
Typical mature size: 6 to 12 feet tall for non-dwarf forms; dwarf cultivars can stay as short as 4 to 5 feet or less in height and width, especially if pruned
Blooms: tapering clusters of numerous small individual flowers, produced at or near the branch tips; flower color range includes white, pink, purple, blue-violet, and reddish-magenta, often with an orange "eye" (throat)
Leaves: simple (not divided into leaflets) with finely or subtly toothed margins; opposite arrangement on the stems; color can be green or varying degrees of silvery-gray, felted in texture, on the upper surface of young leaves; the leaf underside is often distinctly pale in color
A rounded growth habit and arching branches is typical of mature butterfly bush. Photo: Miri Talabac, University of Maryland Extension
Some varieties of butterfly bush have a felted gray coating on the young leaves. Photo: Miri Talabac, University of Maryland Extension
Environmental impacts of butterfly bush
Butterfly bush is an invasive species and spreads into natural areas by seed. Each flower in a cluster produces a capsule containing many tiny seeds, which are dispersed by wind and water.
Butterfly bush can seed into disturbed, open habitats like this riverbank. Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org
Conditions that favor growth
Butterfly bush grows best in sunny, disturbed sites with dry, well-drained soils. It also colonizes riparian areas (sites next to open water) such as stream and river banks.
Alternatives to butterfly bush
Do not plant butterfly bush, and replace existing specimens when possible. The Maryland Department of Agriculture (MDA) regulates the sale of invasive plants and conducts invasive plant species status assessments. Butterfly bush is on a list of species prioritized for assessment in 2026. Refer to the MDA's Invasive Plants Prevention and Control resource page for more information and a list of regulated species.
Some cultivars of butterfly bush are marketed as sterile. Once a species is listed as prohibited, MDA regulations apply to all cultivars of that species unless individual cultivars are later granted an exemption.
Several native or non-invasive shrub and perennial species have flowers highly attractive to butterflies and other pollinators. Candidates include New York ironweed (Vernonia noveboracensis), New England aster (Symphyotrichum novae-angliae), Joe-Pye weed (Eutrochium species), sweet pepperbush (Clethra alnifolia), buttonbush (Cephalanthus occidentalis), butterfly weed (Asclepias tuberosa), blazing star (Liatris spicata), and mountain-mint (Pycnanthemum species).
Kaufman, Sylvan Ramsey & Wallace Kaufman. 2007. Invasive Plants: Guide to Identification and the Impacts and Control of Common North American Species.
Swearingen J., K. Reshetiloff, B. Slattery, and S. Zwicker. 2002. Plant Invaders of Mid-Atlantic Natural Areas. National Park Service and U.S. Fish & Wildlife Service, Washington, DC.
Tallamy, Douglas W. 2007. Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens, Timber Press.
