What is the most advisable product to use to kill Marsh Marigolds in a horse pasture? We have a lot of wildlife on the property as well as horses.
Yamhill County Oregon
Thank you for reaching out to OSU Extension Service. I do not have experience with Marsh marigold specifically, but it is in the buttercup family (Ranunculaceae). We do have resources and recommendations for managing other common species in pastures like Ranuculus repens.
For chemical control, 2,4-D, or 2,4-D + Dicamba (Weedmaster) are good options, especially if applied earlier in the season. Please note that 2,4-D is prone to drift, so extra care should be taken especially if there are highly sensitive crops like grapes in your area. Milestone is another herbicide that is labeled for buttercup control. Read and follow all label instructions carefully. Haying and grazing restrictions which will also be found on the product label.