Although many gardeners never plant crown vetch in landscaping areas, they battle this invasive ground cover as it threatens to spread through desired planting areas. Crown vetch is so energetic that it often chokes out the plants you desire and takes over entire landscapes with its leafy vines and pink flowers. Get rid of crown vetch with persistent eradication techniques that you may have to repeat more than once to get the upper hand.
Cut down the crown vetch as early in the season as possible with the lawn mower or the weed whacker. If you can easily mow the growing area with the lawn mower, mow it down as you would mow grass. If the area is not conducive to mowing, use the weed whacker to cut the crown vetch down to soil level.
Gather all of the crown vetch you cut down and place it directly into the garbage bag. Dispose of the crown vetch immediately without allowing any portions to remain in the growing area.
Apply the glyphosate or triclopyr to the crown vetch while it is in its peak of growing and blossoming. Generally, crown vetch blossoms between July and September. Select a sunny and calm day with temperatures between 60 and 80 degrees F. Apply the herbicide directly to the plant foliage, coating every leaf and stem generously, yet not to the point of the herbicide dripping from the leaves.
Allow the herbicide to work down into the roots of the crown vetch over the following week. Assess the crown vetch after this period elapses. If you still see actively growing portions of the ground cover, reapply the herbicide again in the same fashion.
Pull up all remnants of the crown vetch plants after the herbicide has done its work. Remove all portions of both the foliage and the root system and place everything directly into a garbage bag. Dispose of everything immediately.