Single-storey precast concrete member for a retaining wall or space-lattice wall in which plants can be grown, with a front and a rear longitudinal beam (10 and 14 resp.) which are connected to one another at a distance apart between their ends by cantilever sections (18, 19). In order to manage with fewer structural units and less laying work when erecting the wall and at the same time improve the planting and sound absorption, the perpendicular distance between the top and bottom continuous support surfaces (28 and 30 resp.) of the cantilever sections (18, 19) is at least three to four times as great as the parapet of the front longitudinal beam (10). So that the earth poured into the space-lattice wall does not fall out of the wall over the parapet top edge of the front longitudinal beam, the cantilever sections (18, 19) contain a retaining wall (56) extending over the length of the precast member and forming, for example, a wedge of an angle section (58) (Fig. 18).
