Genus that includes garden hydrangeas, also cultivable in pots, and shrubby hydrangeas. Among the former we report H. macrophylla, with dentate and oval leaves, and globular or flat inflorescence, about 15-20 cm big, which grows in permeable and acid soils, requiring little light and little pruning. Among the latter we report H. petiolaris, also called Climbing Hydrangea, and H. quercifolia, also called Oak-leaved Hydrangea, with white flowers joined in upright clusters.