Provided is a method for producing an agricultural and horticultural granule, the method including molding a powdered agrochemical composition into granules using a lateral extrusion granulator, characterized in that: the lateral extrusion granulator includes a hopper for feeding a kneaded product of the powdered agrochemical composition with water, a screw for kneading and extruding the kneaded product, a screw casing for accommodating the screw, a screen for molding the kneaded product into strands, the screen being provided on a screw casing wall parallel to a screw shaft on a side away from the hopper, and a cooling unit for cooling a screw casing wall on a bearing side of a screw on a side away from the hopper； and the powdered agrochemical composition contains 20 to 80% by weight in total of a component having a water solubility of 4,000 to 500,000 ppm at a water temperature of 20°C and a pH of 3 to 9.
