Projectable sprinklers which rise automatically from the ground when water is supplied under pressure to the sprinklers, sprinkler heads, stationary sprinklers employing the sprinkler head of the present invention for use on the surface of the ground, and a lid apparatus for increasing the area wetted by a sprinkler head. The projectable sprinklers include a generally cylindrical housing closed at the bottom and sunken in the ground, a projectable float which floats upward within the housing when water is supplied under pressure to the sprinkler, and a sprinkler head including a rotating nozzle or nozzles attached to the top of the float. In one embodiment, the projectable sprinkler contains means for spreading chemicals over the surface of the ground. The sprinkler heads include means for pumping solutions or liquid mixtures of chemicals through the nozzle or nozzles of the sprinkler head, and may be used in a stationary or projectable sprinkler system. The stationary sprinklers include the sprinkler heads of the present invention and means for spreading chemicals over the surface wetted by the sprinkler. The lid apparatus includes a disc mounted on top of a sprinkler head having a movable flap therein.