A rotary lawn mower mounted on a tractor is equipped with a blower operable to move grass clippings from the mower into a pair of collection bags. The blower has an impeller located within an upright housing attached to a side of the mower. A belt and pulley drive connects a horizontal impeller shaft to an upright blade shaft of the mower to rotate the impeller concurrently with the grass cutting blades of the mower. The rotating impeller draws grass clippings and other loose material from the mower and discharges the material into collection bags mounted on the rear of the tractor.
