Aeroponic plant growing system

An aeroponic grow tower is provided. The tower includes a modular wall system located between a cover and a base. The wall system includes a plurality of individual flat, four-sided wall panels. The identical wall panels are removably connected along their side edges into one or more levels having a polygonal shape. Levels are aligned and stack atop the base and each other. The wall panels have openings defining grow sites configured to support plants such that foliage extends to the outside and roots hang inside the tower. A pump delivers nutrient solution from the base to a high-rotational speed spray nozzle which aerosolizes the solution. The spray also impacts the interior surface further aerosolizing the solution. Channels direct the solution running down the interior surface to the grow sites which include secondary reservoirs to provide a further source of nutrient solution. A ventilation system and seedling covers are also provided.