An implement, adapted to be towed by a vehicle, has a frame and a plurality of ground engaging tools carried by the frame. Support wheel assemblies carried by the frame are moveable relative the frame to raise and lower the frame between working and non-working positions in which in the working position, the tools engage the ground, and in the non-working position, the tools do not engage the ground. Each wheel assembly is mounted for rotation about a respective wheel steering axis. Coulters are also mounted to the frame and are engagable with the ground only in the working position of the frame. Each coulter is mounted to the frame for rotation about a respective coulter steering axis. Finally, a steering mechanism is operable to turn the wheel assemblies and the coulters each about their respective steering axes to steer the implement.