A prominent plant in some lawns this summer is birdsfoot trefoil (Lotus corniculatus). Grown for pasture and hay, birdsfoot trefoil has escaped to roadsides and waste areas. It is also an occasional weed in lawns as it adapts well to mowing.
Birdsfoot trefoil is a long-lived perennial legume. The plant has an upright spreading growth habit and can reach a height of 2 feet. The dark green leaves of birdsfoot trefoil appear to be composed of 5 leaflets. However, the compound leaves actually consist of 3 leaflets and 2 broad leaf-like stipules at the base of the leaf stalk. Plants produce small, pea-like flowers. Flowers are bright yellow to orange-yellow. A cluster of three to eight flowers are borne atop each flower stalk. The one-inch-long fruits (seed pods) somewhat resemble the toes on a bird's foot, hence the common name of birdsfoot trefoil. At maturity, the pods split and the halves twist, scattering the seeds. In lawns, mowers also help to scatter the seeds.
Birdsfoot trefoil is native to Europe and Asia, but it has become naturalized in parts of the United States. It tolerates compacted, infertile, and poorly drained soils. Birdsfoot trefoil is also drought and salt tolerant.
Birdsfoot trefoil in lawns can be controlled with broadleaf herbicides. Combination products that contain 2,4-D, MCPP, and dicamba are most effective.
This article originally appeared in the July 13, 2001 issue, p. 88.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on July 13, 2001. The information contained within may not be the most current and accurate depending on when it is accessed.