The Burning Bush (Euonymus alatus) is a deciduous shrub famous for its fiery autumn color. While popular in landscaping, this plant has become a widespread environmental concern across parts of North America. Its success in gardens has translated into significant problems for native ecosystems. Understanding its unique characteristics and aggressive nature is the first step toward managing its impact on natural areas.
Botanical Identification and Characteristics
Identifying Euonymus alatus is straightforward due to several distinctive physical traits. The most notable feature is the presence of corky “wings” that run longitudinally along the younger stems, giving the shrub its alternative name, winged euonymus. These four ridges of bark are particularly noticeable in winter after the leaves have dropped.
The shrub typically grows into a dense, multi-stemmed form, reaching heights between 6 and 15 feet. Its dark green leaves are small, one to two inches long, and are arranged oppositely along the branches. In the fall, the foliage changes to a brilliant scarlet or crimson color, earning the plant its popular name.
Inconspicuous greenish-yellow flowers appear in late spring. The fruit that follows consists of small, reddish seed capsules that ripen in the fall and split open. They reveal one to four seeds encased in a fleshy, bright orange-red coating called an aril. This fruit attracts birds, which consume and disperse the seeds far from the parent plant.
History of Introduction and Invasive Status
The shrub originated in East Asia, native to regions including China, Japan, and Korea. It was first introduced to the United States around the 1860s for its ornamental qualities and adaptability. Landscape designers prized the plant for its low-maintenance requirements, dense growth habit, and reliable, intense autumn foliage.
Its popularity led to widespread planting in residential and commercial areas, allowing the shrub to escape cultivation easily. Euonymus alatus is considered invasive because its seeds are highly viable and germinate readily in various conditions. This has allowed it to naturalize in over 25 states, particularly across the eastern and midwestern United States.
The prolific production of seeds, combined with effective dispersal by birds, allows the plant to establish itself quickly in natural areas like woodlands and forest edges. This aggressive spread has resulted in the shrub being classified as an invasive threat in many jurisdictions. Several states, including Massachusetts, New Hampshire, and Pennsylvania, have banned the sale and propagation of Euonymus alatus due to its ecological threat.
Ecological Consequences and Management Strategies
The success of the burning bush stems from its high tolerance for shade and its ability to leaf out earlier and retain foliage later than native species. This extended growing season and dense canopy severely shade the forest floor, significantly reducing the light reaching native wildflowers and tree seedlings. This light deprivation prevents the successful regeneration of native plants, leading to reduced biodiversity and the formation of dense, single-species thickets.
The shrub offers limited nutritional value to native wildlife and pollinators compared to the native plants it displaces. Studies show that areas dominated by Euonymus alatus support lower abundance and diversity of native insects, which are the base of the food web for birds and other animals. Replacing native shrubs with an invasive one disrupts complex ecological relationships, leading to a less resilient habitat.
Management requires a sustained, multi-pronged approach depending on the size of the infestation. Small, young seedlings can be effectively removed by hand-pulling, especially when the soil is moist, ensuring the entire root system is extracted.
For larger, established shrubs, mechanical removal followed by chemical treatment is the most reliable method. This involves cutting the main stem close to the ground and immediately treating the fresh-cut stump with a systemic herbicide, such as glyphosate or triclopyr, to kill the root system and prevent re-sprouting.
Basal bark applications, where an oil-based herbicide is sprayed around the lower 12 to 18 inches of the intact trunk, offer another effective year-round chemical option. Timing is important for foliar sprays, which are most effective when applied to the leaves in the late summer or early fall before the foliage turns color.