An experimental investigation was carried out to analyse the effect of using trees for solar control of buildings by shading. Several physical parameters were measured in two areas, on the same facade, of a building at the Agricultural University of Athens; high trees shaded one area, while the other was clear from any shadow. Comparisons were made for a hot summer period between the physical parameters measured in the shaded and the unshaded areas regarding the air and wall surface temperatures, the heat exchanges between the wall surface and the surrounding environment, the wind speed and the humidity of the air. The results showed that plants constitute an excellent passive system for solar control of buildings offering significant advantages over conventional artificial sunscreens.