Horticulture as a Pathway of Invasive Plant Introductions in the United States

T he majority of plants used in agriculture, forestry, and horticulture in North America are not native to the continent. Most of the plants that have been introduced are not invasive; they carry out their intended purpose and therefore benefit humans in multiple ways, causing no problems. A small portion of introduced plants, however, escape from cultivation and become pests of natural areas. A recent study found that invasive plants, animals, and fungi are second only to habitat loss and degradation in endangering native plant species Fifty-seven percent of the imperiled species studied were negatively affected by nonnative invasive species. The impacts on native species include competition for resources A recent estimate put the economic cost of invasive plants in natural areas, agriculture, and gardens at 35 billion per year