A weed and grass trimmer attachment and riding mowers having weed and grass trimmer attachments are provided. The trimmer attachment attaches to a riding mower using a structural support arm and a mounting member. The trimmer attachment takes power from the mower drive shaft to operate a trimmer attachment. The trimmer attachment includes a floating trimmer shaft that compensates for ground variations. The trimmer attachment enables a seated operator to both mow a lawn and trim grass and weeds.
