An object of the present invention is to provide a plant cultivating unit that can perform a watering operation in a simple manner and can supply water uniformly to plants in locations where a floor surface is sloped, such as the rooftop of a building, without requiring separate water supply piping work. A plant cultivating unit (1) comprises a water storage tray (2) in which water can be stored and in which receivers (3) for housing the roots of plants can be arranged in an interior thereof, a water storage space (8) in the water storage tray (2) and the receivers (3) being communicated via water feeders (7), and the water stored in the water storage space (8) being able to be supplied to the plants via the water feeders (7). The water storage tray (2) is provided with connectors (6) capable of communicably connecting adjacent water storage trays (2) to each other, the connectors (6) being configured from an inflow connector (6a) and an outflow connector (6b), the water flowing in through the inflow connector (6a) to the water storage space (8), and the water being able to flow out through the outflow connector (6b) by an overflow when a specific amount of water is stored in the water storage space (8).
