Abstract: Apparatus for treating lawns which includes a plurality of hoppers calibrated to dispense predetermined amounts of seed and fertilizer, wherein each of the hoppers includes an opening for feeding material therefrom and means are provided for adjusting the hopper feed opening. The adjusting means includes a movable closure bar which slides between an open and closed position for opening and closing each hopper feed opening. The movable closure bar is actuated by a rack and pinion, and the rack is connected to the movable closure bar by a plate member. The closure bar and plate member are arranged to slide relative to a stationary guide. An indicator dial is also provided for indicating the position of the closure bar relative to the hopper feed opening.The hoppers direct the seed and fertilizer to a distribution plate which distributes it over a wide lawn area.