The present invention provides an aeroponic plant growing system with improvement in efficiency, performance, and ease of maintenance. In an embodiment of the present invention, the aeroponic system comprises multiple aeroponic units and water cycle components, LED lights, sensors, and control components to support and operate the aeroponic units. Each aeroponic unit comprises a drainage tank to catch water, manifolds and spray nozzles to irrigate the plant clones, and one or more rooting trays. The rooting tray comprises rooting tubes extended from the apertures in which the plant clones are inserted. The rooting tubes are shaped and arranged in a manner such that a rooting tube shares its walls with its neighboring rooting tubes. In one embodiment, the cross section of a rooting tube is shaped as a hexagon with equal sides and multiple rooting tubes are arranged into a honeycomb structure. In certain embodiments, the aeroponic plant growing system further comprises stem collar trays removably fitting on top of the rooting trays. The stem collar trays have openings in which stem collars can be inserted into.
