Do you Have to mow? Thats not safe being out in weather like that.
NEED to get the seeds/flower heads cut before they go to seed. Remember my "good neighbor" has turned me in before. NOT that his pasture is any better OR his field FULL of hensbane. But he did spray that this year after just going around it last. I think he lost about 20% of the hay off that area this year because of it. So he does know its poison to cattle/bovines.