Assembly kit, which is intended for constructing a plant-base (2) delimitation structure, in which there are walls (1) intended to form side supports for the plant base (2), comprising wall elements (1) attached at the corner to each other, as well as a strip element (4) belonging to each corner joint. The strip element (4) fits on the inside of the corner joint, into a guide slot (6) made, preferably at a distance from the corner of the joint, in each of the wall elements (1) to be attached to each other, in such a way that the strip element (4) installed in the guide slot (6) reinforces the corner joint (5) and restricts the movement of the wall elements (1) relative to each other.
