PROBLEM TO BE SOLVED: To provide a method for solving a problem of harming plants without matching a change in soil moisture due to changes in weather and humidity as an automatic control method for watering potted plants. SOLUTION: The structure of a sensor for detecting moisture in soil 3 is improved to eliminate an ill effect caused by an electrolytic phenomenon in the soil 3 by suppressing an energizing current between sensor electrodes 7. A moisture change in the soil 3 due to watering is thereby detected timely to attain automatic control corresponding to watering and the moisture change in the soil 3. Consequently, a water detection sensor for excess water leaking out of a cultivation container 2 due to watering, is eliminated and cost is reduced. The sensor electrodes 7 are surrounded by a water-absorbing insulating material 7b to prevent an erroneous determination caused by a short circuit between the sensor electrodes due to capillary roots of a plant 1. As to a water source, water can be supplied from a water storage tank 11 without using a water pipe. COPYRIGHT: (C)2013,JPO&INPIT
