A sod harvester in which sod is cut, conveyed upwardly, and then travels downwardly over a floppy conveyor and falls into a roll forming enclosure formed by a bottom conveyor and a vertical conveyor. The floppy conveyor swings downwardly at the start of roll forming, to reduce the free fall of the sod, and swings upwardly as the roll grows. When the roll is formed, the bottom conveyor is unlatched and tilts downwardly to discharge the roll, at the same time pulling into cocked position a core tube injector arm. When the roll discharges, the bottom conveyor snaps upwardly, releasing the core tube injector arm which injects a fresh core tube into the roll forming enclosure. The sod is rolled with its grass side outwardly to facilitate laying and to protect the grass roots. A tray on a cart at the end of the harvester receives the discharge roll and can convey it to either side of the cart. When the tray reaches either side of the cart, a cam tilts the tray to discharge the roll onto the ground clear of the next pass of the harvester.