Submitted to: Equus
Publication Type: Popular Publication
Publication Acceptance Date: 3/14/2005
Publication Date: 5/2/2005
Citation: Singer, J.W. 2005. Equus consultants column - buttercup control in horse pastures. Equus. p.114-115.
Technical Abstract: The buttercup family (RANUNCULACEAE) consists of many native and introduced species. Three members of this family are common pasture weeds: bulbous buttercup (Ranunculus bulbosus L.), tall buttercup (Ranunculus acris L.), and creeping buttercup (Ranunculus repens L.). All three are perennials that reproduce by seed. Creeping buttercup also spreads by above-ground stems called stolons that form roots at the node. The abundance of buttercups in your pasture is probably related to their low palatability, which likely cause your horses to avoid grazing them. This in turn, depending on your mowing/clipping management, may allow them to go to seed and continue the encroachment cycle. Buttercup prefers to grow in moist soil, although it will establish and grow in soils that are well-drained as well. To control buttercup in your pasture, several management practices should be considered. First, because your grazing area is limited, it does not seem reasonable to disrupt a large area using mechanical control, although this can be an effective control tactic. Consequently, chemical control is probably the best strategy to employ to eliminate the buttercup. Your local Cooperative Extension office can provide information on which pasture herbicides are most effective for controlling buttercup. Additionally, there is probably a large quantity of buttercup seed in the soil seedbank that may emerge after your initial control. Following best management practices can reduce future buttercups from emerging. Soil testing to determine potassium, phosphorus, and pH levels will identify deficiencies. Also, adding desirable pasture seed to the soil where the buttercup was growing will help fill in the bare areas. Although broadcasting seed on the soil surface is not as efficient as incorporating it with a drill or other planter, it eliminates soil disturbance. Disturbing the surface soil, where most of the buttercup seed is located, will increase the amount of seed that germinates after your initial control. If you add grass seed to the pasture and the majority of the pasture is grass, adding nitrogen fertilizer will improve the productivity and competitiveness of your pasture plants that will minimize opportunities for weed establishment. Contact your local Cooperative Extension office for recommendations on pasture grasses and nitrogen fertilizer.