Vertical gardens are another way of seeing gardens and of implanting them in unexpected locations within the cities. The plants grow with or without substrate for root growth, i.e., in hydroponic systems or are cultivated soilless. Unlike horticultural crops such systems consist of many species with different requirements and are subject to complex environmental conditions. The physical and physico-chemical fertigation solution is characterized by EC, pH and oxygen content. Also oscillations of temperature, light and humidity need to be considered. The design of the hydroponic systems needs to become adapted to different constructions. Some hydroponic recirculating systems for use in vertical gardening are suggested.