A grass collector for receiving clippings discharged from a port at the rear of a mower housing. The collector is secured to a frame member which is pivotally connected to support members joined to the mower so as to be able to swing between a closed, clippings-receiving position adjacent the rear discharge port and an open, displaced position at which clippings can be dumped from the collector. The position of the collector is selectively controlled by the operator of the mower, and a spring arrangement is provided for retaining the collector in the selected position until over-ridden by the operator.