Abstract: A spreader for dispersing particulate material onto a ground surface, the spreader broadly comprising a frame, a hopper, wheels, an impeller shaft, and an impeller. The hopper includes an opening to allow the particulate material to pass therethrough. The wheels are rotatable relative to the frame. The impeller shaft is rotatable relative to the hopper. The impeller is coupled to the impeller shaft and rotatable therewith. The impeller has opposing first and second sides and includes a plate with opposing first and second surfaces, a first set of vanes, and a second set of vanes. The impeller is shiftable between a first configuration in which the first side faces a first direction and the second side faces a second direction and a second configuration in which the first side faces the second direction and the second side faces the first direction.