Also called purple vetch, this herbaceous perennial vine is native to Europe, southwest Asia, and northern Africa but was introduced into the US for soil improvement and erosion control in the 1950s and has become invasive in some areas. It is a member of the legume family, Fabaceae, that also includes peas, lupines, and mimosa. Crown vetch grows from a perennial crown and has long trailing branched stems that grow up to 6′ long forming a 1-2′ tall mass. The dark green compound leaves are 2-4″ long and consist of 11 to 25 pairs of leaflets that are 1/2 to 3/4″ long. From late spring to fall umbels of 5-20 white, pink or purplish pea-like flowers appear that are 1/2″ wide and consist an upright standard and a lower keel. The fruit is a long slightly kidney shaped pods terminating in a long pointed beak and containing several long, smooth, brown seeds that are thought to be poisonous. The flowers are good in the vase and the plants are an excellent choice for a xeriscape, cutting garden, wildflower garden, and groundcover especially where erosion control is needed, but care must be taken to curb its invasive tendencies in areas where it is rambunctious. The genus name, Securigera, comes from the Latin words securis meaning ax, and gero, meaning bear, and refer to the shape of the pods. The specific epithet, varia, is the Latin word meaning diverse.
Type: Herbaceous perennial vine
Bloom: Umbels of white, pink, to purplish pea-like flowers from late spring to fall
Size: 1-2′ H
Light:Full sun; tolerates some shade
Soil: Average to lean, dry to moderately moist, well-drained
Hardiness: Zones 3-7
Care: low maintenance
Pests and Diseases: None of significance
Propagation: Seed, division
Companion Plants: Whorled milkweed, spreading dogbane, prairie coneflower
Photo Credit:Wikipedia
Creeping stems of the plants quickly form large clumps that can cover and shade out native vegetation and the plant is considered invasive in Connecticut, Indiana, Kentucky, Maryland, Minnesota, Missouri, North Carolina, New Jersey, Oregon, Tennessee, Virginia, and Wisconsin. Plants spread by seeds and rhizomes that can be 10′ long.
Crown vetch grows from a perennial crown and has long trailing branched stems that grow up to 6′ long forming a 2′ tall mass. The dark green compound leaves are 2-4″ long and consist of 11 to 25 pairs of leaflets that are 1/2 to 3/4″ long. From late spring to late summer 1″ wide umbels of 5-20 pinkish flowers appear on that are on long stalks and comprised of a single upper petal that is pink, and two side petals that are often white. The fruit is a long slender pods containing several long, smooth, brown seeds that are thought to be poisonous. Crown vetch prefers full sun and dry to moist soil in USDA Hardiness Zones 3-7. It is intolerant of flooded soil or shade .
Since then it has spread and naturalized in the northeastern US where it can be found in a variety of sites such as fields, grasslands, prairies, roadsides, waste areas and natural areas. Creeping stems of the plants quickly form large clumps that can cover and shade out native vegetation and the plant is considered invasive in Connecticut, Indiana, Kentucky, Maryland, Minnesota, Missouri, North Carolina, New Jersey, Oregon, Tennessee, Virginia, and Wisconsin. Plants spread by seeds and rhizomes that can be 10′ long.