Abstract: A seedling tray has intercalating seedling cavities extending oppositely from mouth openings in top and bottom faces of the tray to bottom regions near to the said faces, thereby rendering the tray reversible. Each seedling cavity converges from its mouth opening to its bottom region which as a bottom opening. In use, the seedling tray has a plurality of upwardly open seedling cavities filled with a suitable growing medium such as soil or mulch. Seeds are planted in such medium in each upwardly open cavity. Inverted seedling cavities act as air ventilation passages extending upwardly and are interspersed between the planted seedling cavities. The air ventilation passages intercalate with and are spaced uniformly between the planted seedling cavities. When the seeds have germinated and developed into seedlings, the seedlings may be transplanted as desired.