The device i.e. cultivating panel (1), has a substrate layer (3) made of a fibrous material comprising primary fibers whose one of two sides is applied directly in contact with a surface of another substrate layer (4). The other layer is made of another fibrous material comprising secondary fibers. The latter layer cooperates with a water supplying unit (9). The former layer has thickness and dryness equal to that of the latter layer. The former layer has water absorption ability higher than that of the latter layer, and dry bulk density lower than that of the latter layer.
