Guide to Growing Climbing Hydrangea + False Hydrangea Vine
Though most hydrangeas are flowering shrubs, forming big, upright, multi-stemmed plants, there is a one notable exception that is familiar to many: the climbing hydrangea, H. anomala subsp. petiolaris. This anomaly (as you can tell from its scientific name!) naturally grows as a woody vine, meandering its way up trees in the wild, and in gardens, up chimneys, brick walls, pergolas, and railings as well.
False hydrangea vine is a close cousin to the climbing hydrangea. They are in the same botanical family, the Hydrangeaceae, but false hydrangea vine is known as Schizophragma (usually pronounced sky-ZO-frag-muh). The difference between these two is that the sterile florets of climbing hydrangea have 4-5 sepals each, and the sterile florets of false hydrangea vine are single, sail-like sepals. All of the care instructions below apply equally to both types.
Climbing hydrangea is hardy to USDA zone 4 with a native range that includes most of China and into Russia; false hydrangea vine is generally a bit less cold tolerant, usually only to USDA zone 5, with a few varieties on the market hardy only to USDA zone 7.
Both plants reach lengths of 40'+ at maturity but since they are slow-growing, it takes quite a while for them to get there. Width is harder to quantify, as they kind of self-manage their width to the structure they are growing on.
If you picture a climbing hydrangea vine growing up a tree in the wild, that will give you a good sense of the kind of light conditions it prefers: filtered light from a high, leafy canopy. They can take dense shade, but flowering will be severely impacted.
Grow in moist, well-drained soil. If planting at the base of a tree, be sure to provide some additional water specifically to the vine so that the tree doesn't take it all for itself.
Little fertilizer is needed. Climbing hydrangeas are naturally slow to establish, and fertilizing is unlikely to help. If you wish, a yearly application in early spring should be more than sufficient for its needs.
Planting + Training
Patience is a virtue, and it's fairly required when it comes to growing a climbing hydrangea or false hydrangea vine. These do take a few seasons to get established, though they will reward you with decades of beauty. When you plant a climbing hydrangea, it is unlikely to cling to its support that first season. If you wish, you can use some garden twine to gently suggest to it that it ought to be growing upward and to keep it out of the way, but this isn't strictly necessary. For the plant to begin clinging to its support on its own, it must first create new vegetative growth, and this doesn't normally happen until its second season. If that new shoot is on its structure, rootlets should begin to form later that season. Be patient, and keep an eye on your plant. It generally takes at least 3 seasons for it to begin blooming, though varieties like Flirty Girl false hydrangea vine, were selected to bloom at a younger age.
Climbing hydrangeas all bloom white; a few varieties of false-hydrangea vine boast pink and red tones on their sterile florets, but the central fertile florets will still be white.
Both climbing hydrangea and false hydrangea vine bloom on old wood. They generally need little pruning, but if you do need to prune, trimming or cutting back the plant will likely result in the removal of some flower buds. You can selectively trim out branches if you need to in order to keep it within the confines of the structure you are growing it on.
Climbing hydrangea problems
These hydrangeas are very trouble-free and rarely exhibit even the leaf spot that often pops up on other types. They are, however, susceptible to deer browsing, and the flowers are at the highest risk of being munched.