Standard seedling trays measure 540 mm × 280 mm, with the number of cells ranging from 18 to 800 depending on the diameter of each cell. Seedling trays with 72–288 cells are ideal for cultivating medium‑ and small‑sized seedlings. Cell shapes are primarily circular and square: circular cells promote deeper root penetration and robust root network development, while square cells typically hold about 30% more growing medium, ensuring more even moisture distribution and more comprehensive root system growth.