A feller head for use with a prime mover in harvesting trees has a grapple that defines a cavity having a vertical axis. The cavity is designed to receive a tree to be harvested along the vertical axis. A cutter blade is mounted below the grapple. The cutter blade is suitable for cutting through the tree being harvested and defines a cutting plane along which the tree is cut. An adjustable mounting mounts the cutter blade to the grapple and permits pivotal movement of the cutting plane about a roll axis and a pitch axis. An actuator controls the pivotal movement of the cutting plane about the roll axis and the pitch axis.
