Abstract: A plant-growing apparatus (10) has a plurality of rotatable plant-growing modules (32) which can be moved between two positions, separated vertically or horizontally. Each module (32) comprises a cylindrical structure for holding plant-growing containers (80) in which the plants grow radially inwardly of the cylindrical structure toward a light source (68). The apparatus (10) has module support means for supporting each module and rotating it in a substantially horizontal position. The apparatus has module moving means, for example sprocket driven chains (20, 22), for conveying the modules between the two positions.