Seedling tray - 40 seed cells - fit for round net pot - durable, long lasting - reusable Seedling tray, also called seed starting tray - a plastic tray designed with multiple small cups to hold seedlings. It is a very useful gardening tool that allow users to plant 1-2 seeds in each cell, during the germination stage. Until the seedlings are ready for transplantation, it could be moved to a bigger pots/containers.