Friday, October 11, 2013

Forest Invasive Contributes to Fall Foliage Colors

Invasive Species to Watch:  Winged Burning Bush

That’s invasive!? Winged burning bush (Euonymus alatus) is a favored plant in landscaping, and many people are unaware of its aggressive, invasive tendencies once the seeds are dispersed by birds. There are many cultivars of burning bush - loved for its brilliant red fall foliage and its ability to be pruned and shaped into almost any form. Burning bush is hardy up to zone 4, and grows in almost any soil conditions except continually moist soils - one of the reasons it is often overused in the landscape. However, there is a dark side to this horticultural favorite - so dark that it is now banned for sale and propagation in Connecticut, Massachusetts, and New Hampshire. In a study on its invasiveness, cultivars had an estimated seed production that ranged from 588 to 3763 seeds per plant, and 40% of seeds could produce new plants. Therefore, each year, it is conservatively estimated that one burning bush on private property may be sending more than 235 young plants into adjacent land. These new seedlings have the potential to form dense thickets and displace the local native plant species.

It is easily distinguished from native and other invasive look-alikes by the greyish-brown, corky, winged structures on the young green stems. Leaves are about 2 inches long, elliptical with a pointed tip, finely toothed along edges, and oppositely paired along the stem. Small flowers with four yellowish-green petals appear in May. Green fruits mature throughout the summer. In the fall, the outside fruit capsules turn red to brownish-purple and split to reveal fleshy, red arils, which birds disperse. Depending on the cultivar, plants may reach heights of 12 feet tall or more. Unfortunately, burning bush is becoming a common sight in the forests of southern Illinois and is no longer recommended for planting by conscientious land managers. Although a sterile cultivar of burning bush has been developed, there are several native alternatives, which offer very attractive replacements in landscaping, such as red chokeberry (Aronia arbutifolia), large fothergilla (Fothergilla major), Virginia sweetspire (Itea virginica), Blackhaw (Viburn prunifolium), shining sumac (Rhus copallinum), and Eastern wahoo (Euonymus atropurpureus).

There are several ways to control burning bush. Small seedlings can be hand-pulled. Shrubs can be cut and treated with a systemic herbicide, such as glyphosate or triclopyr. Cut surfaces should be treated with herbicide in less than 10 minutes following cutting, so that the cut surface does not dry and prevent herbicide uptake. A basal bark application of herbicide (triclopyr in oil) may also be used if cutting the plant is not desirable. A foliar herbicide application may be used at a low rate (2 – 4%) for small plants. Always follow label instructions when applying herbicides and wear the appropriate protective gear.  

Please help encourage others to landscape with native or non-invasive species. If you find escaped burning bush in Illinois natural areas, please report these sightings by visiting EDDMaps at the River to River CWMA website (  Please contact Karla Gage, CWMA coordinator, with questions: 618-998-5920 or  

Reference: Brand, M. H., Lubell, J. D. & Lehrer, J. M. Fecundity of Winged Euonymus Cultivars and Their Ability to Invade Various Natural Environments. HortScience 47, 1029–1033 (2012). 

Article originally published in the September 2013 Williamson County Soil and Water Conservation District newsletter.