Abstract: A vacuum system adapted for mounting to a riding lawn mower. The vacuum system includes a blower section removably mountable to the mower deck of the mower, a unit for delivering power from a drive system on the mower deck to a propeller within the blower section, a trailer section configured for towing behind the mower, a hitch system for connecting the trailer section to the rear of the mower, and a passage connecting the blower section to the trailer section and through which debris discharged by the mower deck is propelled into the hopper. The blower section has a housing that receives debris discharged from the mower deck and a device for propelling the debris through an outlet of the housing. The hitch system permits pivoting of the trailer section about lateral and fore-aft axes of the mower but not about a vertical axis, such that the trailer section remains aligned with the fore-aft axis of the mower when the mower is turning.