Buttercup Weed Management

Last year many people were dismayed to find a sea of yellow flowers in their pasture when spring rolled around. While buttercups can be pretty to look at and a sure sign that spring has arrived, their toxicity to livestock and their invasive nature make them a very unwanted sight in a pasture. 

Buttercup is a short-lived perennial weed that behaves more like a winter annual. It begins to germinate in the fall and grows into the spring when the weather warms up. It has characteristic shiny, bright yellow flowers with five petals. This weed thrives in pastures where there is little competition, such as overgrazed areas or bare patches.

All parts of the plant are toxic to livestock and can cause blistering in the mouth and internal parts of the digestive tract, diarrhea, colic, and even death in extreme cases. However, buttercup is bitter and most horses will refuse to eat it as long as other forage options are available. The toxin that causes these issues will not be active when the buttercup is dried, so it is not a concern in hay.

Since buttercup starts growth in the fall, it is important to have a thick stand of grass that will prevent the new seedlings from taking root. Proper fertilization and grazing management in the fall will help encourage this thick stand. Avoid overgrazing throughout the winter to prevent creating an environment that is favorable to buttercup growth.

When buttercups are present, mowing in the spring can help reduce flowers and therefore seed development. But mowing alone will not eliminate the plant and the problems it poses.

Chemical control is a very effective strategy, but it is important to utilize this method early. Once it flowers, the plant is too mature for herbicides to have effective control. The ideal time to apply herbicides is late February through early March while the weeds are still small. 2,4-D is an effective herbicide that provides good control when applied early. Other effective herbicide options include aminopyralids (eg. GrazonNext), 2,4-D + dicamba (eg. WeedMaster), triclopyr (eg. Crossbow), or metsulfuron (eg. Cimmaron). Picking the right product can depend on other weeds you need to control at the same time. 

If your pasture had issues with buttercup last year, you can count on them being back again this year. Start scouting early and be prepared to utilize control methods.  If infestations have been heavy in the past, do not expect this problem to go away after one herbicide application. It can take several years of timely chemical control to get the buttercup under control. Always encourage a thick healthy stand of grass to help reduce weed pressure.