Abstract: An automatic irrigation system in which a plurality of zones of a ground area are periodically watered for a predetermined time in a predetermined sequence. Located within each zone is a ground moisture sensor that overrides the automatic irrigation system and prevents watering if the sensed ground moisture is at or above a chosen value. Apparatus is provided which, from a central location, can bypass the automatic irrigation system and the ground sensors. A central transmitter coupled to a plurality of remote receivers enables simultaneous or sequential watering of all zones by actuating the remotely located valves regardless of the sensed ground moisture level.