The invention relates to a trimming machine for trimming low shoots in tree plantations to be assembled in a tractor (1) by means of a fixed frame (2) with respect to which a mobile frame (5) moves in height with vertical movement, to which frame there are associated longitudinal cutting mechanisms (12). On each side there is a first articulation part (14) on which the angular orientation of the longitudinal cutting mechanism (12) is fixed, and it has a second articulation part (16) provided with rotating movement to which there is fixed the second fixing means (15) establishing the inclination of the longitudinal cutting mechanism (12) with respect to the vertical to define a working or transport position. It additionally has a protecting device (17) coupled to the first articulation part (14) protecting the longitudinal cutting mechanism (12), causing the retraction thereof due to the rotation of the second articulation part (16) in the horizontal plane.
