To provide a plant trimming apparatus and method therefor capable of stably providing a trimmed plant having high quality in high efficiency necessitating little manpower.

The trimming apparatus 5 is provided with a base member (supporting bed 6), a transfer member (chain member 11) supported by the base member in freely movable (circulatable) manner, a rotary supporting device (cup member 25) rotatably supported by the transfer member and capable of supporting a plant 1, a transfer driving means to move the transfer member, a rotation driving means 8 to rotate the rotary supporting device and a trimming means (electric cutter 9) to trim the plant supported by the rotating rotary supporting device. A rounded plant 1 having good appearance can be produced by the apparatus 5.