We have found the best and least expensive is winter wheat. They really hit it in the evening just prior to dark. Winter wheat is easy to plant, a drill works best, but we have broadcast it and used a drag to work it in. It also works great as a food source all year. After the crop matures (July)and the seed drops to the ground you will get "volunteer" growth. When it starts to re-grow, mow it and they will come right back to it. Then in Sept. re-plant.