Leafy spurge appears as a weed in most of the United States and Canadian provinces, being a particular problem in states in the north and central Plains. It grows well in pastures, woodlands, rangelands, and along roadsides. It is in state invasive species laws in Massachusetts, New York, Michigan, and other northern Midwest states plus most western states. It also appears on the invasive list in Indiana and Kentucky. The problem with leafy spurge is that it displaces native grasses and its extensive roots and early spring growth help it outcompetes other species for light, water, and nutrients. It is toxic to cattle and horses, and its sap can irritate skin. Control involves burning, mowing, tilling, and the use of herbicides.