water-holding section for holding planting water supplied to the planting space [Z). The water—needing section has a water discharge opening ',12； for overflow. In a horizontal position (A) in which the planting space (2) opens upward, i_he DO'-nom WS.J~L -.J.- amoi ois sice V3_LJ.3 { — } renn a horizontal, water-holding section for holding planting water. In a vertical position in which the planting space (2) opens sideways, a vertical water-holding secxion for holding planting water is formed by the bottom wall (3), side walls (4), and a dam section (8) formed facing the bottom wall (3) on the side wall (4) that is the bottom surface. A water discharge start section of the water discharge opening (12) is located at a position a predetermined distance away from the bottom wall (3) and a predetermined distance away from a side wall (4) .
