Securigera varia, known in Kentucky as Purple Crown Vetch, is a low-growing legume (pea family) vine. It is commonly used throughout the United States for erosion control, roadside planting and soil rehabilitation. Although it is considered an introduced invasive plant, it is a beautiful flower to see blooming along roadsides.
Crown Vetch grows 1 to 2 feet tall and bears small clusters of 1/2-inch pink and white flowers from early summer to late fall. Crown Vetch is a tough, aggressive spreading plant so it is not recommended for a small home garden because it will grow up small trees and shrubs. However, it is well suited to a sunny bank, where it will grow with little maintenance. Its deep roots and thick, fern-like leaves provide excellent erosion control where it is used as a ground cover.
Although Crown Vetch is a pretty plant to look at from a far, a wise gardener should practice caution before introducing into the home garden. This is one flower I enjoy when driving the highways of Kentucky, but I do not grow it in my own gardens.
Please note: Crown vetch is toxic to horses because of the presence of nitroglycosides. If consumed in large amounts, it can cause slow growth, paralysis, or even death.