A Black Medic weed can be identified by its taproot, which does not creep by rooting at the nodes. Its stems are hairy, growing upright and somewhat square, and its elliptical leaves grow alternately with pinnately trifoliolate ends. Lower leaves on these broadleaf weeds have longer petioles than the upper leaves. Black Medic also produces small, yellow flowers that are clustered on the end of the stalk.
This broadleaf weed is found throughout much of the United States and is typically more active in soils with low nitrogen levels. The type of soil and climate Black Medic is found in can determine its life cycle.
Good cultural weed control practices should be sufficient to keep Medicago lupulina at bay, including proper mowing and watering practices. Maintaining proper levels of macronutrients in your lawn’s soil can also help discourage this broadleaf weed.