An aeroponic plant growing system with vertically aligned planting sites. The system includes a plurality of plant-holding containers, a walled enclosure, and a fluid dispenser housed therein. One of the enclosure's walls defines a plant-supporting frame on which are formed horizontally extending, outwardly-facing grooves and their respective inwardly-projecting ridges. Tapered between its distal ends, each container can be individually received within one of a plurality of spaced apart orifices defined by each groove. So received, the container extends into the enclosure and a substantial portion of the container's transverse cross-section most distal from its wider end is cantilevered over each horizontally extending ridge situated downwardly of that particular container's interface with the frame, thus positioning, in use, the taproots of large numbers of plants within a barrier-free, vertical corridor of extremely narrow footprint down which their roots can grow both aeroponically and gravitropically.