A vegetation trimming and edging device has an adjustable head (12) that permits selective positioning between trimming and edging orientations. A shaft (14) extends between the head and a handle. The head receives one end of the shaft. A coupling mechanism (26) couples the head and shaft, and locks the head against rotational movement about the shaft. In particular, the coupling mechanism includes a locking structure and a bias mechanism. The bias mechanism urges the locking structure into engagement to prevent rotational movement of the head. Downward pressure applied to the head overcomes the bias, however, and disengages the locking mechanism for rotation of the head between trimming and edging modes. When the downward pressure is released, the locking mechanism is again engaged to lock the head in position for the desired operational mode.