A trimmer head or trimmer head assembly for a trimmer is provided herein. The trimmer head may include a base plate defining an axial direction, a pivot head, and a blade retainer. The pivot head may be attached to the base plate. The blade retainer may include a radial arm rotatably mounted to the base plate to rotate relative to the base plate between a first position at which the radial arm is circumferentially aligned with the pivot head and a second position at which the radial arm is circumferentially spaced apart from the pivot head.
