Method for the culture supernatant of a number of plants (9), comprising providing a shaped support panel (3) with continuous apertures (6) for said plants (9) and provide a water supply (8), wherein said support (3) is in said water supply floatingly and where, for each of said plants to be cultivated, the roots (12) of said plant or its precursor is placed with a small amount of substrate in a space containing intermediate air (10) in one of the openings in said support at a distance from said water supply (8) so that said root (12) of said plant (9) or its precursor are positioned at a vertical distance ( a) of said water supply, where that part of the support which faces towards the water surface has a number of recesses which form chambers (7) which are gas tight towards an upper side of the support and are open towards a underside of the support, so that the surface area bounded by the perimeter of said shaped support panel is greater than the surface area of said support is actually in contact with water, where, within the outer perimeter of said support, at least 20% of the area surface water side of said support is not in contact with water of said water supply, where the surface area of the shaped support panel is not in contact with the water in the water side is at least 50% greater than the total surface area of the openings in said upper side, wherein in a first phase of growth of the plant or its precursor, at least a significant part of moisture requirements of the plant or its precursor is satisfied by said interspace (10) between said support (3) and said water supply and / or said support, and plants are sprayed from above, wherein the height of said gap corresponding at least to the length ( 1) of the root of said plant at the end of said first growth phase, and where, in other second growth phase of the plant, at least 90% of moisture requirements of the plant is satisfied directly by said supply water, and said first phase of growth compr
