A capillary plant comprising: - at least one water reservoir, - at least one watertight trough having a height and comprising a trough bottom, a circumferential sidewall and an opening, wherein the opening represents a face arranged opposite the trough bottom and is delimited by that edge of the circumferential sidewall which is arranged opposite the trough bottom, and wherein the height extends from the trough bottom to the opening, - at least one water inflow device having means for generating and/or maintaining an inflow of water from the at least one water reservoir into the at least one watertight trough, wherein a distance between the water inflow device and the trough bottom is not greater than one third of the height of the watertight trough, - at least one overflow protection device, wherein the overflow protection device connects the at least one watertight trough to the at least one water reservoir in such a manner that a watertight connection is established, and - at least one organic and/or inorganic substrate that is arranged in the at least one watertight trough and that exhibits capillary action, characterized in that the capillary plant can be arranged in the soil in such a manner that the trough bottom is arranged opposite the upper terrain edge of the soil and the opening is arranged between the trough bottom and the upper terrain edge and the distance between the trough bottom and the upper terrain edge is equal to or greater than the height of the watertight trough, that the capillary plant has a further watertight trough with a trough bottom, at least one circumferential sidewall and an opening, wherein the opening represents a face arranged opposite the trough bottom and is delimited by that edge of the at least one circumferential sidewall which is arranged opposite the trough bottom, wherein the volume of the further watertight trough is greater than the volume of the watertight trough and wherein the further watertight trough can be arranged in the soil in such a manner that the watertight trough is arranged in the further watertight trough and the openings (20, 21) are positioned at the upper terrain edge, and that the additional watertight trough has a lockable drain, wherein the drain connects the additional watertight trough to the water reservoir and/or to a collecting and/or control shaft in such a manner that a watertight connection is established. - at least one water reservoir, - at least one watertight trough having a height and comprising a trough bottom, a circumferential sidewall and an opening, wherein the opening represents a face arranged opposite the trough bottom and is delimited by that edge of the circumferential sidewall which is arranged opposite the trough bottom, and wherein the height extends from the trough bottom to the opening, - at least one water inflow device having means for generating and/or maintaining an inflow of water from the at least one water reservoir into the at least one watertight trough, wherein a distance between the water inflow device and the trough bottom is not greater than one third of the height of the watertight trough, - at least one overflow protection device, wherein the overflow protection device connects the at least one watertight trough to the at least one water reservoir in such a manner that a watertight connection is established, and - at least one organic and/or inorganic substrate that is arranged in the at least one watertight trough and that exhibits capillary action, characterized in that