Growing system for growing plants, for example vegetables and ornamental plants, comprising a container tray (1) which is floatably arranged in a liquid reservoir (14). The container tray (1) is configured to float on nutrient water (6) during use and has at least one opening (4) which is arranged in a tray bottom (2) of the container tray (1) for bringing a growth substrate (11) which is arranged on the container tray (1) into contact with the nutrient water (6). The container tray (1) is a substantially flat container tray (1) which comprises an upright tray edge (3), and wherein the at least one opening (4) has an upright opening edge (5) having a height which is such that the growth substrate (11) is situated above a water line of the nutrient water (6) during use.