Climbing hydrangeas are striking even when they are not in full bloom. With dark cinnamon or reddish vines and dark green shiny heart shaped foliage, they are attractive all year round. In early to midsummer they add snowy white lacecap flowers to the picture.
"The stems of climbing hydrangea leave a residue that is very difficult to remove," according to The United States National Arboretum. Climbing hydrangeas can also cause damage to walls as they grow if they are allowed to climb up the side of a house or other building. The tiny roots that hydrangea uses to anchor itself will dig into the surface. Wood siding or stucco will eventually be degraded by these little roots.
Provide something for it to climb on that is at least 6 to 8 inches away from the wall of the building. A lattice climbing structure or trellis provides excellent support for the climbing hydrangea to grow on.
Slugs and snails can be a problem for climbing hydrangeas and other types of hydrangeas as well. There are many possible options for slug and snail removal. Frogs and toads can be moved into the garden to eat them. A deep saucer or shallow can placed near the plant with beer in it will attract the slugs and drown them when they crawl into it. Slug and snail bait can be used to get rid of them or they can be removed by hand.
Thrips, spittlebugs, aphids and mites can be a problem with climbing hydrangeas. Insecticidal soap can be used to eliminate these pests. Aphids will generally go away on their own as the new hydrangea growth matures, since they prefer young new leaves.
Mites can be difficult to control, since pesticides are not always effective against them. Mites tend to become a problem when the weather is hot and dry. The best defence against mites is to keep the plant properly watered and healthy.
Powdery mildew and black spot can be a problem for climbing hydrangeas. Plants growing in shady humid conditions with restricted air flow are especially susceptible. Remove weeds and trim back any other plants around the climbing hydrangea to improve air circulation. Prune away and remove the affected leaves from the garden area. Do not add them to compost piles; instead put them in the trash to be hauled away. Rust spots can also be a problem for this plant. Water early in the morning so that the leaves will dry before the hot afternoon sun or in the early evening to allow the water to dry before nightfall.