An aeroponic plant-growth system includes growth space and a control unit that may be assembled using factory made modules. The growth space includes layers at different heights, and each layer includes plant holders and misters positioned to apply a mist to roots of plants in the plant holders. The control unit employs a controller to execute a program that operates a liquid supply system to provide liquid flows to the misters in the layers. Each of the liquid flows may be regulated according to the height of the layers.