Abstract: A mower for harvesting crop includes windrow forming housing where crop is discharged after being cut. A windrow grouper attachment includes a crop conveyor attached to the main frame of the mower by a vertically swingable support which is selectively disposable in a lowered working position where it intercepts crop exiting the windrow forming housing and transfers it side ways and in a raised non-use position wherein it permits crop exiting from the mower to be deposited into a windrow directly behind the mower. The vertically swingable support for the crop conveyor is mounted to a slide that is in turn mounted for shifting laterally on a transverse beam of the mower main frame. By selectively manipulating the conveyor among its working, non-use and shifted positions, it is possible to deposit three windrows alongside each other for being subsequently picked up together for processing by another machine, such as an ensilage harvester, for example.