A blade sharpener comprises a work surface consisting of a single support line. A grinding wheel defines a plane that contains the support line. The grinding wheel is swingable in the grinding wheel plane to a selected position relative to the support line. A blade is supported on the support line in a manner that produces a first cutting surface on the blade cutting edge. The single support line enables mulching blades to be sharpened without having to impart angular motions in space to them as they are fed past the grinding wheel. The grinding wheel is swingable to different positions relative to the support line, thereby enabling the grinding wheel to produce different cutting surfaces on the blades. Swinging of the grinding wheel is achieved by mounting it to a plate that pivots about an axis perpendicular to the grinding wheel plane. A mobile work table having a top plate of finite area is selectively retainable over and removable from the single line support.