Getting Rid of Yellow Buttercup Weeds in Horse Pasture
We're in Franklin County and have 3 old quarter horses grazing in a 3.5 acre field. The front half is covered with yellow buttercup. We know it's poisonous, but so far the horses seem to be ok they don't eat it. Our question is how do you safely get rid of it? We can keep the horses off it as long as necessary, but is that necessary if you have it mowed? We've had the farm 25 years, and this is the very first time this has happened.
Buttercup grows here as a winter annual weed, and so these will begin disappearing over the next few weeks as weather gets warmer. There are two strategies for managing these - the first is focused on thickening your current grass stand. The best time to reseed pasture with typical pasture grasses is late August-September. Make sure you have soil tested and adjust fertility as needed for the health of the grass. Also prevent horses from overgrazing pastures - continual close grazing reduces the grass's ability to spread and come back next season. A thick, healthy stand of pasture grass reduces the chances for buttercups or other weeds moving in.
The second strategy is to use herbicide sprays - the best time to spray for buttercup is late February through early April (while they are young and before they flower/produce seeds). This link includes herbicide options for control of buttercups
Buttercups are among several weeds that contain toxins -- in most cases, animals tend to avoid toxic plants unless there is nothing else to eat. I'm not sure that mowing is necessary, but it may help prevent some of the seeds from maturing.