A windrow merger including three pickup and transfer units, a folding system, and a plurality of float mechanisms. The folding system employs simultaneous rearward, outward, and upward folding motion so as to ensure none of the units interfere with the other units while folding, and likewise while unfolding. The folding system can further fold and unfold each of the three pickup and transfer units at the same time. During merging operations, the plurality of float mechanisms of the windrow merger limits the range of motion of each pickup and transfer unit. The float mechanisms further transfer a portion of the weight of each pickup and transfer unit from the ground to the frame of the merger. The units of the windrow merger can also include a rub rail having a surface that reduces swirling or clumping of material as the material is conveyed toward an end of the windrow merger.
