Climbing hydrangeas feature large, fragrant clusters of white flowers that bloom in late spring and summer against a backdrop of dark green, heart-shaped foliage. These massive vines readily climb columns, trees, and other supporting structures. A climbing hydrangea plant grows 30 to 80 feet (9-24 m.) tall, but it tolerates pruning to shorter heights. You can also grow it as a shrub. Info on Climbing Hydrangeas Climbing hydrangeas (Hydrangea anomala subsp. petiolaris) are large, heavy vines that need substantial support. A climbing hydrangea plant clings to the supporting structure by two methods — twining vines that wrap themselves around the structure, and aerial roots that grow along the main stem cling to vertical surfaces. The flower clusters consist of a central mass of tiny, fertile flowers surrounded by a ring of larger, infertile flowers. You can leave drying flower clusters on the vine after they bloom, and they will keep their shape and add interest, even after the foliage begins to fall. The fertile flowers may also produce seed pods for propagating, if desired.