Crown Vetch

Common Name: Crown Vetch
Scientific Name: Securigera varia (L.) Lassen (formerly Coronilla varia L.)

Legal Status

Restricted

Propagation and sale of this plant are prohibited in Minnesota. Transportation is only allowed when in compliance with Minnesota Statute 18.82. Although Restricted Noxious Weeds are not required to be controlled or eradicated by law, landowners are strongly encouraged to manage these invasive plants on their properties in order to reduce spread into new areas. 

Background

Crown Vetch is native to central and eastern Europe and the Caucasus region of Asia. It was introduced to the United States in the mid-1800s and became widely planted by the 1950s as a groundcover, cover crop, and bank and slope stabilizer along roads and waterways. It is now found throughout the continental United States and in most Minnesota counties. In Minnesota, it has been planted as a cover crop and used for soil stabilization, but its use has declined due to its invasive nature.

Description

• Crown vetch is an herbaceous perennial in the legume family.
• Stems grow to 2 to 6 feet long in a trailing, creeping pattern.
• Leaves are dark green and pinnately compound, with 15 to 25 pairs of oblong leaflets.
• Flowers are small umbels, pinkish lavender to white, borne in clusters at the end of leaf axils. Blooming occurs from May through August.
• Fruits are 2 to 3 inches long, flattened, finger-shaped pods borne in crownlike clusters, and contain many small seeds.
• Roots are aggressive rhizomes that grow horizontally up to 10 feet and produce new plants.

Habitat

Crown vetch readily invades prairies, dunes, woodland edges, streambanks, pastures, rights of way, and roadsides. It prefers open, sunny habitats and tolerates all different soil types, including saline and alkaline soils, as well as drought conditions.

Means of spread and distribution

Crown vetch spreads by seed and vegetatively through rhizomes. It can be introduced to new areas through movement of soil infested with rhizome fragments. Historically, its primary spread has been through intentional planting. Some research suggests deer and other small animals move crown vetch seeds to new areas.

Crown vetch is found in most Minnesota counties.

Impact

Crown vetch overtakes and suppresses other vegetation, reducing species diversity and wildlife habitat. Due to its creeping growth habit, it can cover and shade out other plants and eventually form dense monocultures. Over time, infestations can cover several acres.

Prevention and management

• Once established, crown vetch is difficult to control. For all management options, infested sites must be monitored for several years and treated repeatedly until the seedbanks are depleted.
• Do not plant crown vetch. Use alternative cover crops or native plants for soil stabilization.
• Mowing can slow the spread if done on schedule to prevent seed formation, and for successive years. For eradication, mowing must be performed in conjunction with another control method, such as herbicide application.
• Prescribed burning in late spring over several consecutive years is an effective control method. Make sure to contact the Minnesota Department of Natural Resources to learn more about control burning practices and regulations.
• Large infestations can be controlled by spot-spraying with foliar herbicide applications. If using herbicide treatments, check with your local University of Minnesota Extension Agent, co-op, or certified landscape care expert for assistance and recommendations. There are several businesses throughout the state with certified herbicide applicators that can be hired to perform chemical applications.

Toxicity

There are conflicting reports of crown vetch alternatively causing pasture bloat in livestock, while others suggest it is safe for cattle to graze.