A device for trimming the edge of a lawn device comprises a rotary cutter which, in use, rotates about an axis which is substantially horizontal with respect to the ground. The device further comprises a guide (14) which is mounted to extend, in use, in a substantially vertical downward direction to a depth greater than or substantially equal to the depth to which the rotary cutter extends. The guide (14) is preferably mounted to extend, in use, in a substantially vertical downward direction to a depth greater than or substantially equal to the depth to which the rotary cutter extends. <IMAGE>
