A planting baseplate assembly comprises a base, a water storage device, and a diversion element. The base includes a base body a drain hole penetrating the upper and lower surfaces of the base body, wherein a connection member extends downward from the lower surface of the base body a plurality of water guiding trenches mutually intersecting on the upper surface of the base body and interconnecting with the drain holes for water drainage and a plurality of overflow holes disposed in and penetrated the water guiding trenches for water drainage. The water storage device includes a storage body and a connection neck to fix with the connection member. The diversion element is inserted through the drain hole and extended to the water storage device. The planting baseplate assembly is easy to assemble, favorable to environmental protection, and applicable to green roofs and various planting apparatuses.
