The more a pasture can be divided, the easier it will be to manage. Portable fencing can be very helpful for pasture subdivisions. This causes some of the pasture to be overgrazed, while the rest is under-grazed. Keeping the pasture clipped will help reduce this problem and keep the whole pasture in the vegetative, edible stage. Use the easiest, most efficient way available to mow down the tall grass, weeds, and undesirable plants.
Spot spraying with a selective herbicide can also be helpful for weed control.
Overseed When Applicable Even good pastures thin out over time. New seed should be added annually to ensure that your pastures produce good grass. Existing grasses may re-seed themselves, but they probably won't be the ones you, or your horses are looking for. Naturally, the weeds will easily re-seed and spread. Don't wait until the weeds take over.