A couple things to consider: Mulching effectively requires the deck making a 'seal' with the grass. If the grass is sparse, patchy, or just really dry, then when the blades try to disperse the clippings back into the ground it may result in dirt/dust blowout from under the deck. The only way to truly mulch is to use eXmark mulching blades, with the mulch kit. A lot of times we hear customers using our eXtreme style blade (blade with the 'teeth' on the airfoil), and just covering up the discharge opening. These style blades are still side-discharge blades, so when the discharge opening is covered up, there's no place for the debris to go and it blows out of the front of the deck and onto the operator.