Disclosed is a method for manufacturing a container (2) from a blank (3) made of plastic material, in a stretch-blow molding unit (7) including: a mold (11) provided with a wall (13) and a mold base (14) which is axially movable relative to the wall (13) between a low position and a raised position; a stretch rod (22) which is axially movable relative to the mold (11) between a high position and a low position; the method including: a phase of inserting the blank (3) in the mold (11); a phase of stretch-blow molding; a phase of boxing; a phase of determining the start and end of the boxing phase, respectively, by detecting the movement of the rod (22) from the low position thereof and the stopping of the rod (22) at the raised position thereof.