Crown Vetch, a Wild Flower That Can Be Used for Erosion Control
I was admiring some lovely pink flowers growing on an embankment one day. A fellow Master Gardener said that it was crown vetch and that it is used for erosion control. What a pretty way to deal with a terrible problem.
What is Crown Vetch?
Crown vetch is native to Europe, Africa and Asia. It is a member of the legume family which also includes peas and beans. The plants grow 1- to 2-feet in height. The flowers can be white, pink or purple and appear in the early summer. Bees and other pollinators love them. Crown vetch is hardy in USDA growing zones 3 through 9.
Why is it used for erosion control?
Crown vetch has tough, tenacious roots which anchor the soil in place. Its dense foliage shades out other plants preventing weeds from gaining a foothold. The plants grow very quickly and can become invasive if planted in a formal garden. Because it prefers poor soil, it will grow for years with no fertilizing and no mowing. These four characteristics make it an ideal ground cover for stabilizing slopes, erosion control and roadside plantings.
How do I grow it?
Crown vetch can be grown three ways: seed, crown division and root division. Root division is probably the easiest to do. Simply dig up a plant, cut the roots into 4 inch sections and replant them. The root divisions will send up new shoots.
Crown divisions are almost as easy. Simply dig up a plant, then cut it into sections and replant the sections to same depth as the original plant, with the crown of the plant even with the top of the soil.
Whether you are using root divisions or crown division, plant them 2 feet apart. The plants will grow quickly and aggressively, rapidly filling in the spaces between them. In some Midwestern states, crown vetch is considered an invasive species. Once it is established, it is difficult to eradicate.
Growing crown vetch from seed is more difficult. In nature, the seeds can take up to six months to germinate. You can hurry that process along in one of two ways. Either soak your seeds for four hours in water that is 190⁰F to soften the seed coat or rub the seeds between two pieces of sandpaper to “damage” the seed coat which will allow water in and the seedling out. Then plant your pretreated seeds directly into the soil where you want the plants to grow and barely cover them with soil. They need some sunlight to germinate.
Can I grow it anywhere?
Crown vetch likes dry, well-drained soil. If planted in soil that is constantly wet or drains poorly, the roots and crown will rot. Don’t plant it along streams, lakes or irrigation ditches. The plants grow best in full sun but they will tolerate a little shade. They won’t grow at all in full shade.
Once established, crown vetch will grow happily for years with no watering, fertilizing or mowing required.