The invention concerns an exclusively mechanical stand-alone device (60) for controlled watering by sprinkling, wherein a soil simulating member, consisting of an absorbent body (82) associated with a reclinable cup (74) arranged beneath, contributes to the determination of the interval between two watering operations, based on the soil characteristics a balance arm (78) bearing said absorbent body (82) and an annular magnet (80), mounted cantilevered oscillating on a shaft (76) and balanced by a compressed spring (86), contributes to the determination of the opening and closing times of a valve (10) said valve comprises a hydraulic relay (38) with a nozzle (52) triggering its opening or closure, in response to the displacement of the magnet field (80), via a bistable ferromagnetic core (48) secured to the nozzle (52) an impermeable sleeve (42) encloses said core (48) and said nozzle (52) a sliding canopy (108) protecting the absorbent body (82), enables one of the parameters determining the duration of the watering operation to be adjusted a thermostatic element (88) with retractable stop (102) with adjustable position prevents any watering in bright sunshine the framework of said device (60) is mounted rotating on a pivot consisting of the base (44) of the sleeve (42) and a tail unit (106) makes it steerable like a vane, so as to better take into account the soil-drying wind. Said device is simple, economical and efficient. The invention is applicable to stand-alone automatic control of watering (without electric supply), taking into account all the parameters involved (soil and environment).Dans un dispositif autonome et purement mécanique (60), de commande darrosage par aspersion, un organe simulateur de sol, constitué par un corps absorbant- (82) associée à une coupelle inclinable (74) disposée, en dessous, participe, à la détermination de lintervalle entre deux arrosages, en fonction des caractéristiques du sol un bras de fléau (78), portant ce corps absorban
