A lawn mower blade assembly is described that comprising a generally flat, elongated blade having a central mounting opening for mounting of the blade to a rotating motor shaft of a lawn mower. The blade further includes a plurality of bit openings positioned along the blade, and a plurality of elongated, generally cylindrical bits for insertion into the bit openings. Each bit has a head and a plurality of rib protrusions located slightly away from the head at one end of the bit. Each bit is inserted into one of the bit openings from the bottom side of the blade, past the rib protrusions, and snapped into place against the head. As such, each bit is held in place in the bit opening by the rib protrusions and the head. The bit, once installed, each extend generally perpendicularly from the top surface of the blade. The bits are each long enough such that when the bald assembly is installed in a lawm mower, the distal end of the bits make contact with and bend over slightly against an underside of a blade compartment of the lawn mower. When the blade is rotating, grass or other lawn debris, particularly wet such debris, is prevented from sticking to and building up upon the underside. The blade may further include a lifted flange at trailing edges of the blade that provide a high velocity air stream within a blade compartment of the lawn mower to further prevent the build-up of wet grass or the like within the compartment.