Without seeing the site and management, it is a hard question to answer. Minimizing soil disturbance and maintaining good soil cover is always a good place to start to prevent or keep weeds in check. When there is good vegetative cover and the soil surface is protected, there is less opportunity for weed seeds to germinate and get started. It happens to everyone; if you leave the cows in a spot too long, especially combined with a heavy rain event, you open up the sod for opportunistic weeds. The threshold of how many weeds are too many weeds is certainly different from person to person. My threshold is hit quickly at 30% canopy. When weeds start occupying 30% of the canopy, intervention is needed because it is robbing sunlight from desirable forages. Weeds that are noxious or very invasive should also be kept from going to seed.

Your pastures are weedy ‘cause the grass ain’t getting a fair shot. Either it’s been overgrazed, underfed, or just plain worn out. When the good stuff gets chewed down too hard or the soil’s tired, weeds see the opening and move in fast.

Could be your cows are hitting the same spots too often, or the grass ain’t getting time to bounce back. Bare patches pop up, and next thing you know, you’ve got thistles, ragweed, and all sorts of junk filling the gaps.