purple flowering invasive butterfly bush

Butterflybush (Buddleja davidii). Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Updated: April 13, 2021

About butterfly bush (Buddleja davidii)

Life cycle/information: Butterfly bush, also called summer lilac, is a deciduous shrub bearing wands of purple, pink, or white flowers at the branch tips from summer to fall. Introduced from Asia around 1900, butterfly bush has escaped cultivated plantings and is found in wild areas of at least 20 states. It crowds out native plants that would provide essential food for butterflies, birds, and other wildlife.

Growth habit: Fast growing and invasive. This woody shrub grows 3-15’ tall in a single season. Leaves are opposite, pale-gray, with toothed or wavy margins. Flowers are grouped in a cluster at the branch tips and bloom from mid-summer to fall. Flowers can be purple, pink, lilac, or white, with yellow to orange centers. Abundant nectar is attractive to adult butterflies, but no native North American butterfly caterpillars can use butterfly bush as a host plant food source. Without host plants for caterpillars, butterflies cannot survive.

butterfly bush

Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Reproduction: Each flower produces a capsule containing many small seeds. Seeds are dispersed by wind and water. Butterfly bushes do not spread vegetatively.

Conditions that favor growth: Establishes in sunny, dry, disturbed sites with well-drained soils. It also colonizes riparian areas such as stream and river banks.
 

invasive butterfly bush infestation

Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

What to plant instead:  New York Ironweed (Vernonia noveboracensis), New England Aster (Symphyotrichum novae-angliae), Sweet Pepperbush (Clethra alnifolia), Virginia Sweetspire (Itea virginica), Butterfly Weed (Asclepias tuberosa), Blazing Star (Liatris spicata)

Controlling butterfly bush

Dig out plants. Remove spent flowers before they set seeds.

Additional resources and references

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.

Compiled by Christa Carignan, reviewed by Debra Ricigliano, University of Maryland Extension, 5/2018