A native of Eurasia, where it is controlled by natural enemies, leafy spurge readily adapts to a variety of situations. It infests, and if not aggressively managed, can dominate landscapes ranging from open prairie and hillsides to riparian areas and lowlands. The deep-rooted and prolific perennial has doubled in acreage every 10 years since the early 1900s, and is expanding beyond its foothold in the western United States.
With a head start of more than 100 years before control efforts were initiated, (see Leafy Spurge Timeline) leafy spurge is a tenacious opponent that cannot be eliminated or managed by any single entity or control tool. A collaborative, integrated, area-wide approach is essential to solving this costly weed problem.
The economic impact of leafy spurge is staggering. Infestations in the Dakotas, Montana and Wyoming alone are estimated to cost agricultural producers and taxpayers $144 million a year in production losses, control expenses and other impacts to the economy. Every AUM (Animal Unit Month: the amount of grazing required to sustain a cow/calf pair, or six sheep, for one month) lost to leafy spurge infestations costs $167 in lost economic activity. Leafy spurge has literally forced some ranchers out of business.
Its impact, however, cannot be measured in dollars alone. Leafy spurge crowds out native vegetation, resulting in a monoculture that reduces biodiversity and threatens both abundant and sensitive species. The invasion of exotic weed species in national parks, wildlife refuges and other lands set aside for wildlife and recreation has, in fact, reached epidemic proportions. In addition, the most commonly used control tool herbicides often have adverse environmental consequences.
In short, leafy spurge is an economic and environmental catastrophe for ranchers, land managers and taxpayers in the U.S. and Canada.