Buttercup is a winter annual board leaf weed that will take over a pasture and turn it yellow, according to Lance Rice, Lafayette County Agent.
Cattle may graze on it early in the spring but once it matures and the yellow flowers appear, they will often refuse it. Buttercup is a very competitive weed in the early spring and will compete with other forages allowing it to take over a pasture turning it yellow with small flowers.
While this weed is very prevalent across the state and appear to be a problem, it is very easy to control. The best time to treat pastures is late February to early March. An application of 2,4-D Amine at 1-2 pints/acre at this time will yield excellent control of buttercup. In dormant bermudagrass pastures or hay fields, an early application of Glyphosate or Paraquat will also provide excellent control. Always read the label before use.