It’s a hard-hearted gardener who can resist the charms of a climbing hydrangea, but it's important to know how to grow and care for these special plants. Growing vigorously, yet mannerly, under conditions in which many vines would wither, this standout will brighten any dark spot in your landscape, and, always the polite plant, the climbing hydrangea will ask little of you in return.
Climbing hydrangeas are characterized by white clusters of flowers similar in appearance to those of lacecap hydrangeas. The leaves are glossy green and rounded, although in some cultivars the leaves are variegated, providing additional punch. These blooms virtually glow in shady corners and the long twilights of late June and early July. In winter, the cinnamon colored, exfoliating bark gives additional interest.
Climbing hydrangeas are exceptionally unfussy; they will thrive in all levels of light. Southern gardeners may want to err on the side of caution, however, selecting a site that tends more towards the shady. Climbing hydrangeas prefer moist, well-drained soils, although if conditions are less than ideal, you can plant the root ball a few inches higher than the level of the ground, sloping the dirt up to meet the top of the root ball. If soil quality is not an issue, plant it even with ground level in a hole at least twice the size of the pot. It is always a good idea to add some organic materials to existing soil, such as compost, aged manure, or peat moss. Give your plant a nice, long drink of water, then a good layer of mulch to help it retain moisture.
Climbing hydrangeas need some sort of sturdy structure to climb upon. They are vines, after all. Unlike many other climbers, they will not require any sort of open framework such as wire fencing or trellis to grown on, nor will they require you to do any tying. Like ivy, climbing hydrangea attaches itself via tiny rootlets along the stems, fastening to vertical surfaces with ease. While it will grow up just about anything, it should not be allowed to do so. Growing this vine on the sides of buildings should be done with caution. Moisture will be retained against wood sidings, creating ideal conditions for rot. When branches are removed, rootlets will leave their mark, so planting against vinyl or aluminum siding is not advised. Masonry walls, fences, sturdy exterior structures like arbors and pergolas are all good candidates. Even a mature tree trunk is an option.
Water your climbing hydrangea regularly and deeply. Growth and initial bloom on these plants is often slow to start because the roots require a little time to adjust to their new surroundings. Remember the old gardening rhyme: First year it sleeps, next it creeps, then it leaps! Patience is a virtue, in this case, and once established, the climbing hydrangea will pay you back tenfold. Like some of its shrubby cousins, climbing hydrangeas bloom on old wood, so pruning should be minimal, if at all, in their early years. Once mature, pruning may be done immediately following bloom.