black medic weed

Black Medic (Medicago lupulina). Photo: Karan A. Rawlins, University of Georgia, Bugwood.org

Updated: July 26, 2021

General description

  • Black medic is usually first noticed when it produces numerous round yellow flowers in clover like clusters. Flowers eventually form black seedpods that persist on dark brown to black prostrate stems. A legume that is a summer annual with alternate compound leaves with 3 leaflets that closely resembles clover. Toothed stipules are present at the petiole bases. Forms a shallow taproot with small nodules. Often mistaken for wood sorrel (Oxalis).

Photos

Leaves

Black medic leaves

Photo: Bruce Ackley, The Ohio State University, Bugwood.org

Flowers

Black medic flowers

Photo: Karan A. Rawlins, University of Georgia, Bugwood.org

Growth habit

Black medic plants spreading over rocks

Photo: Forest and Kim Starr, Starr Environmental, Bugwood.org

Management in lawns

Cultural lawn care practices

Maintain healthy, dense turf that can compete and prevent weed establishment.

Mechanical management

Hand pulling or using an appropriate weeding tool are the primary means of mechanical weed control in lawns. This is a viable option at the beginning of an infestation and on young weeds. Hand pulling when the soil is moist makes the task easier. Weeds with tap roots like dandelions or have a basal rosette (leaves clustered close to the ground) like plantain are easier to pull than weeds such as Bermudagrass (wiregrass) or creeping Charlie (ground ivy) that spread with stolons or creeping stems that root along the ground.

Chemical treatment in lawns

Herbicides should be used as a last resort because of the potential risks to people, animals, and the environment. Be aware of these lawn herbicide precautions first. 

If you chose this option, spot treat weeds with a liquid, selective, postemergent, broadleaf weed killer applied when weeds are actively growing. Look for a product with one or more of the following active ingredients: 2, 4-D, MCPP (mecoprop), Dicamba* or Triclopyr.

*Do not spray herbicides containing dicamba over the root zone of trees and shrubs. Roots can absorb the product possibly causing plant damage. Refer to the product label for precautions.