Weed-opedia: Black Medic
Black Medic (Medicago Lupulina)
What does it look like?: Black Medic (also known as hop clover) is a legume with a central taproot that has several branches spreading up to 18 inches wide. It has yellow pom-pom shaped blossoms and teardrop shaped leaves. Mature flowers form a black seedpod, which is where its name comes from.
What causes it?: Compacted soil and/or low nitrogen levels.
When does it show up?: Blossoms mostly April to June, but can bloom until fall.
Best treatment plan: Fall treatments are best for prevention. However, this weed is easily pulled by hand. Also, improving the soil–by aerating, replenishing nitrogen levels and maybe adding organic material, will get rid of the environment they like best. Keeping your lawn mowing height a little higher can help too, as this weed doesn’t like shade. You can also use a chemical herbicide. Call a professional for a free quote.
How long will it take to get rid of it?: Can be easily eradicated with soil improvement and fall treatment, combined with hand pulling.