A colorful, apparently innocuous shrub that can grow over 10 or 15 feet tall, the winged euonymus displays wild fall color ranging from light pink to fire red. In March, before leaves sprout, it’s easily identified by unusual “wings” on side branches.
In full sun it grows densely and vigorously, responds well to trimming, shaping and even shearing, is easy to mulch, forms a dense root mass that crowds out competitors and casts a deep uniform shade. These convenient qualities have resulted in widespread mass plantings along highways and as hedges in commercial and residential landscapes. In shadier settings such as mature forests and field edges, euonymus grows less densely but multiplies rapidly, creating vast colonies that choke out native plants and reduce plant diversity.
Why it’s a problem
Humans imported euonymus to Europe and the U.S. from China before 1900 and it continues to be widely planted in many states, including Connecticut. Like most invasive imports, euonymus has some built-in qualities that help it gain control over large areas of woodlands and open spaces. Deer don’t like it, preferring its endangered neighboring natives. Birds eat the seeds and help distribute them. It tolerates a wide range of light, soil and moisture conditions. It is monoecious—male and female reproductive parts are present in each flower—so that one plant can alone produce many more. And we humans crave dramatic fall colors in simple dependable plants.
What to do
Don’t plant it. All varieties that produce seed contribute to invasive dominance. For hardcore lovers of euonymus, there is hope: a UConn team led by Professor Li Yi has developed a sterile (triploid, seedless) version that can be safely planted without spreading unchecked. Apparently, however, it is not yet commercially available.
Instead, plant native alternatives that increase diversity and feed insects and mammals. These include the American wahoo (euonymus atropurpureus), dwarf fothergilla (fothergilla gardenia), spicebush (lindera benzoin) and highbush blueberry (vaccinium corymbosum).
Pull or dig out small euonymus plants, weakest in the early spring before leaf growth starts.
For larger shrubs, cut to the ground, and then cut the regrowth for several years to gradually exhaust the nutrients stored in the plant’s roots. Or cut and carefully paint stumps with small amounts of liquid herbicide, mid-summer to early fall, when nutrients are being transmitted to the roots but not in spring, when nutrients flow the opposite direction. Do not spray herbicides, as this will likely harm struggling nearby natives.
February’s Invasive Action Day was cancelled due to a superabundance of snow. Saturday, March 13, 9 a.m. to noon, is the next opportunity for Granby neighbors to combine efforts to bring back balance to our fields, forests and farmlands. All are welcome. For more information, call or text David at 860-508-0107, or visit GranbyInvasivePlants.weebly.com