Climbing hydrangea is a hydrangea cultivar which has been bred to climb as a vine, rather than to develop as a shrub. This plant can be used in a wide variety of settings in the garden, and there is no upper limit on the growth of climbing hydrangea, except for available space. When well cared-for, this vine can exceed 80 feet (24 meters) in height, and it can be quite distinctive, with a very thick trunk, sturdy branches, and cascading leaves.
This plant is formally known as Hydrangea anomala ssp. petiolaris. It appears to be native to the coastal regions of Japan and China, preferring woodlands, where plenty of climbing material is available. It thrives in USDA zones four through seven, preferring temperate climates, as a general rule. While it can survive in more extreme temperature zones, freezing temperatures and excessively high temperatures can overwhelm climbing hydrangea.
The leaves of climbing hydrangea are dark green, glossy, and heart-shaped. When the bark is visible under the heavy leaves, it proves to be a reddish-brown color, and in the height of summer, the plant produces lacy white flowers which fade away after several months. Hydrangeas tend to produce blooms which are excellent for cutting and displaying in the home or drying, and climbing hydrangea is no exception.
Climbing hydrangea can be trained to climb a trellis, gazebo, or similar support structure, and it will also grow on trees, fences, rock walls, and houses. Many gardeners prefer to provide support for climbing hydrangea, because the plant can scar or damage a house, and if repairs need to be made to the home, the plant may be damaged in the process. By giving climbing hydrangea a separate trellis, gardeners can protect the plant and the home.
This plant needs partial to full shade, making it rather distinctive among the flowering vines. Most vines prefer partial to full sun, but hydrangeas will actually struggle to grow under these conditions. The soil should be rich, moist, and loamy, and if drainage is poor, it can be a good idea to amend the soil to promote drainage. Mulching is not advised, as it can promote rot in the roots. Pruning can be used to shape climbing hydrangea, although the plant should only be lightly pruned to prevent damage.
Some garden stores carry this plant, especially if they specialize in Asian plants. It is also possible to order climbing hydrangea through a garden store or nursery supplier.