Leafy Spurge Poses Noxious Threat

A silent, noxious invader, taking the form of a seemingly harmless perennial plant, daily conducts a relentless assault on America's native prairies and ecosystems.

Listed as a regulated noxious weed in nearly 20 states, leafy spurge poses a significant environmental hazard, choking out desirable forbs and vegetation and wreaking havoc on wildlife habitat, according to reports by the U.S. Department of Agriculture Research Service.

"Leafy spurge is clearly one of the biggest enemies of the western U.S.," said Dr. Jennifer Vollmer, weed scientist with BASF. "It displaces native vegetation, degrades natural habitats and forms a monoculture that can reduce grass production by 75 percent in infested fields and prairies."

Leafy spurge is an exotic European perennial that was first documented in the eastern United States in the early 1800s. According to recent reports, leafy spurge now infests more than five million acres in 35 states, with the most extensive infestations reported in Montana, North Dakota, Nebraska, South Dakota and Wyoming.

"One reason for leafy spurge's success in establishing throughout the U.S. is the lack of natural enemies that suppress its populations in European ecosystems," Vollmer noted. "As a result, the plant has been able to succeed in a variety of habitats throughout North America."

Identifying ways to manage leafy spurge has been especially challenging, because the plant's deep root system makes it especially resistant to most control efforts, including grazing and cultivation. While biological controls have shown promise in some areas, landowners and wildlife managers looking for greater success are exploring the use of targeted "smart" herbicides to provide effective long-term control of leafy spurge.