Black Medic

Medicago lupulina

General Information: Black Medic can be both an annual and perennial weed. It is very similar in appearance to Lesser Trefoil (Yellow Suckling Clover), however Black Medic is less common than Lesser Trefoil, especially on fine turf as it is usually confined to neglected lawns. The main difference and the best way to distinguish between the two weeds, is that the seed pods turn black at the end of the season on Black Medic (see pictures below).

Leaf: Black Medic leaves form as 3 leaflets similar in appearance to White Clover and Lesser Trefoil. The leaflets of Black medic can have a pointed tip (not always the case), which is not seen on the others.

Flower: The small yellow flowers can be seen between the months of April and October. Again similar to Yellow Suckling Clover, but when ripe the pods turn black on Black Medic.

Preferred Habitat: Black Medic prefers nutrient deficient, dry soils, particularly on lawns that have been neglected.

Cultural control: As this weed is an annual hand weeding can prove effective, especially if the plants are few in number. Maintain good turf vigour with a balanced feed program, this will encourage a thick coverage of grass to help discourage weeds invading. Regular light scarification or raking prior to mowing will help remove and weaken Black Medic.

Chemical Control: If however they have spread into larger patches, chemical control will be necessary using a selective weed killer from the list below. In most cases more than one application will be needed for successful control, as Black medic is a stubborn weed to control with chemicals. Once the weed has been removed or controlled the bare area can be filled with a mixture of suitable soil and grass seed to aid recovery.