A modular commercial plant cloning system and method for stimulating root growth from a plant stem. The system includes a supporting frame, a light source, a fluid reservoir, and a cooling element. The supporting frame further includes a plurality of mounting points for securing a plant holding device tray at a desired height and spacing within the supporting frame below the light source. The plant holding device tray houses a plurality of plant holding devices that the plant stems are placed in during the cloning process. The lower end of the supporting frame includes the fluid reservoir, wherein the fluid reservoir further includes a cooling element therein. Additionally, the fluid delivery system helps transport fluid from the fluid reservoir to the sprayer nozzles which are configured to distribute fluid across the plant stems disposed within the plant holding device tray.