Abstract: The planter box is constructed preferably of wooden planks having two opposite side members, two opposite end members and a bottom member, each of the side members having a mortise extending parallel and inwardly from the opposite end of the planks to receive the edges of the end members; the bottom plank is provided with a mortise extending about its upper surface and adjacent the peripheral edges of the bottom to receive the adjacent edges of the side and end members to form a water-tight joint between the side, end and bottom members throughout the box.