Abstract: A plant watering system comprising a sensor (20) buried in the soil (32) in the root region of a plant (40), the sensor (20) passing a low voltage current through the soil (32) to measure the moisture content of the soil (32) and with the sensor (20) being switched on and off in a pulse like manner. The detected moisture level is processed by the system and water supplied to the plant when said moisture level is below a predetermined moisture level for that particular plant or group of plants (40). The systems predetermined moisture level may be adjusted to account for different plants within the system and to stimulate different growth cycles of the plant. The sensor (20) may also determine when said predetermined moisture has been reached and then terminate said supply. The electric current stimulates plant growth and the intermittent operation of the sensor helps prevent corrosion of the sensor and reduces power consumption.