Hydrangea anomala subsp. petiolaris- Climbing Hydrangea

Hydrangea petiolaris is undoubtedly the most well-known and spectacular of all climbing hydrangeas, and one of the few climbing plants that can flower even in the north. This plant is actually a vigorous climbing or creeping bush, with deciduous foliage that is bright green, turning yellow in autumn. It clings to its support using its tendrils equipped with climbing roots. It takes a little longer to establish, but when it matures, it produces a sumptuous flowering in umbels of white lace that turn green before fading. Ideal for north or west-facing exposures, this plant is sensitive to sunburn and appreciates a fertile, deep, and not too dry soil.

Native to Japan and northeastern Asia, Hydrangea anomalis subsp. petiolaris is a climbing bush belonging to the hydrangea family, like its cousin the hydrangea. In its natural environment, the forests of Asia, this woody plant grows up to 15m (49ft) in height, but rarely exceeds 5 to 7m (23ft) in our climates.

This hydrangea has oval, dentate, deciduous leaves. This vigorous climber produces woody, robust, and well-branched stems, up to 3-4m (10-13ft) in height, which have a very interesting architecture. With age, they crack and their bark flakes off in spectacular shreds, giving the plant an attractive appearance even in winter. A creeping bush with strong covering power, it also climbs thanks to climbing roots. Without support, it will not exceed 1.5m (4ft 11in) and will form a dense bush. Its growth is a bit slow in the juvenile stage. This hydrangea blooms in June-July, even in shade. Its nectar-rich flowers, in large umbels sometimes reaching 20cm (7.9in) in diameter, resemble umbrellas, flat and white, with a light but sweet fragrance. They transform this bush into a fine and vaporous mass. They do not fade but dry slowly on the plant, adopting subtle green shades before turning brown. Its foliage takes on a beautiful golden hue in autumn. It is not a heathland plant, and its hardiness can exceed -20°C.

This climbing hydrangea can be used in the background to cover a north-facing wall or dress up an old dead tree or unsightly structure, but it also proves to be an excellent ground cover, very useful for retaining sloping soils. It pairs well with bush fuchsias (magellanica), for example, or with low-maintenance ground cover plants like Aegopodium podagraria 'Variegata', Alchemilla mollis, Geranium macrorrhizum, hostas, or Tiarella. It can be combined with climbing annuals or perennials like morning glories or sweet peas (in a slightly sunny exposure). In any case, it should be planted in a sunny to semi-shaded exposure, in a moist to wet soil. It can also be pruned to obtain a flat shape. Finally, it can also be used in large pots.