The invention relates to safety improvements for mowers incorporating a chipper, and/or catcher. The invention provides safety improvements that only allow operation of the chipper when the mower is below a predetermined threshold ride height. The mower may include one or more side skirts to prevent body parts from entering the cutting zone under the mower, and may have a rear flap including a sub-flap. The mower is arranged so that the sub flap remains closed when a catcher is installed.