FIELD: agriculture.SUBSTANCE: invention relates to the field of crop production and can be used for watering greenhouses and gardens. Plant for watering plants includes metering tank 1 with outlet nozzle 5 for draining water into water distribution system 23, float 15 with stem 16 with valve 17 for shutting off the drain opening of outlet nozzle 5 and pipeline 11 with shut-off valve 10 for supplying water. Metering tank 1 is provided with vertical wall 6 and waste siphon 4 mounted on the upper part of the vertical wall dividing metering tank 1 into two sections-chambers. One of the sections of chambers 3 is sealed with a siphon outlet and outlet 5 for draining water into water distribution system 23. Float 15 is provided with lid 18 of ferromagnetic metal, where seal 20 is located, and guides 21. At the outlet of siphon 4 permanent magnets 19 for fixing the float in the upper position after its ascent and seal 22 are installed, which together with the seal of cover 18 of float 5 at surfacing thereof provides
