Crown vetch is an ornamental plant from the legume family that produces appealing pink flowers with long stems. Because of its invasive qualities, there are attempts to control crown vetch to keep it from being a menace to native plants. Crown vetch is no longer commonly used as a slop ground cover; however, it can be purchased for residential use.
Crown vetch is a perennial herb plant that is part of the legume family. It is considered an invasive species, because it spreads quickly through a strong series of rhizomes. The rhizomes grow horizontally and can reach a length of 10 feet. Along with strong rhizomes, crown vetch seeds are hardy and will start new plants easily.
The plant has a 2- to 6-foot stem with about 15 to 25 sets of oblong leaves. The flowers bloom in May through August and appear as flat-topped, umbel clusters of pink, lavender or white. In winter, crown vetch looks like large patches of brown growth. Crown vetch grows in sunny, open areas.
Crown vetch originated in the Mediterranean area of Europe, Southwest Asia and North Africa. The plant was brought to the United States in the 1950s for use as erosion control. Crown vetch was planted along sloped roads and waterways and used as a crop fertilizer. Because of the ornamental appeal of the flowers, it also was sold commercially.
Crown vetch has become invasive to prairie areas and dunes. The plant is commonly found on the edge of woodlands and riverbeds. Because crown vetch spreads quickly, it has become invasive to native plants. The plant will shade and cover native plants, causing them to choke off. Crown vetch also affects the nitrogen levels of the plant communities, altering the natural levels needed by other plants.
Crown vetch is forage that does not cause bloat in animals, making it appealing as a food source. The protein and fiber content of crown vetch is similar to other legume hay varieties. In some cases, crown vetch is difficult to wilt and dry for proper hay making.
Control and Management
Herbicides are widely used as a method of crown vetch control. These chemicals are sprayed on infested areas starting in early spring. Mowing and controlled burning of areas is used as a method of control, but it must be repeated several times a year for up to two years. Manually removing crown vetch from waterways is used for control, however, it is time consuming because it requires carefully removing all sections of the plant, including rhizomes.