Spiraea van-houttei (Briot.) Zabel has often been used for urban landscaping and for the biological recultivation of ash deposits in Serbia. This study examines its photosynthetic efficiency, water balance, and trace element content in the ‘Stara Zvezdara’ park in the city of Belgrade, in the fly ash deposits of the ‘Nikola Tesla – A’ thermoelectric power plant in Obrenovac, and at the Arboretum of Belgrade’s Faculty of Forestry. Site-dependent variations were found in the water saturation deficit, photosynthetic efficiency, Cu and Mn concentrations, and leaf damage symptoms. The higher water saturation deficit measured in the city park showed some difficulties in maintaining water balance due to Pb accumulation in leaves and the chlorotic damage caused predominantly by car exhaust pollutants. A photosynthetic efficiency (0.787) within the optimum range indicated the capacity of this species to tolerate the elevated concentrations of pollutants in the city air. However, the low photosynthetic efficiency (0.588) and the deficiency of Cu (2.380μg/g) and Mn (9.550μg/g) that caused leaf wilting indicated that the spiraea would probably disappear from the fly ash deposits in spite of a favourable water balance.