The invention relates to a device comprising a trough (2) with a base wall (4) and side walls (5), said trough (2) designed to contain a liquid and a tray (3) for placing in the trough (2), for supporting a growing substrate with at least one well (15), the bottom of which communicates with the liquid in the trough (2) each of which has an adjacent breaking zone (7, 12), the cutting of which permits the device to be divided up.
