Despite its showy, cloverlike flower blossoms and usefulness at controlling erosion, crown vetch (Coronilla varia) can p be an invasive garden nuisance. In its growing areas of U.S. Department of Agriculture plant hardiness zones 4 through 9, crown vetch multiplies quickly through underground rhizomes and seed dispersal. You can mow or hand pull crown vetch, but this is not always enough to completely rid a garden of the plants. Herbicide treatment will get rid of a crown vetch plant before it can multiply and get out of control.
Spray the entire plant with a ready-to-use triclopyr herbicide, which should be 1 1/2 to 2 percent. Wait seven to 10 days for the triclopyr to take effect. The leaves of the crown vetch should wilt, dry and die.
Spray the plant a second time after this period if the plant doesn't die.
Grasp the base of the dead crown vetch and pull it out of the ground, along with as much of the roots as possible. Discard the plants in a green materials waste bin. Wear gloves when pulling the plant.
Loosen the soil carefully to a depth of about 3 inches and pull out any remaining root pieces you find as you dig. Start by digging an area about 2 feet in diameter and slowly increase the area if you continue to find root pieces. Successfully removing the crown vetch depends on completely removing all foliage and root pieces.
Things You Will Need
- Ready-to-use 1 1/2 to 2 percent triclopyr herbicide
- Gardening gloves
- Trowel or hoe
- Monitor the area carefully and treat new crown vetch plants with herbicide as soon as they develop.
- If you only had one crown vetch plant to get rid of, the likelihood of new growth is low. If you have a large patch of crown vetch plants, treat each plant in the same way. You might need to monitor and treat the area repeatedly for up to a year to completely rid a garden of crown vetch if it is not treated as soon as you notice the first plant.
- Keep children and pets away when you're using herbicides and don't allow them in the yard until the herbicide has dried.
- Floridata: Coronilla Varia
- Missouri Department of Conservation: Crown Vetch Control
- State of Indiana Invasive Plant Species Assessment Working Group: Crown Vetch
- Penn State Extension: How Can I Get Rid of Crown Vetch?
- USDA Natural Resources Conservation Service: Crownvetch
- Missouri Botanical Garden: Control and Identification of Invasive Species
- Perennials: Coronilla Varia