Hydrangea petiolaris Cordifolia- Climbing Hydrangea

Hydrangea anomala subsp. petiolaris var. cordifolia is a rare form of climbing hydrangea which prefers to creep along the soil, although some of its branches may rise a little if they find a support at their disposal. It is also characterised by cordate leaves which are smaller than those of the classic Hydrangea petiolaris. It's a curious bush with deciduous foliage that uses it climbing roots to cling to stones and weave among other plants. Its flowering in summer is full of charm, in umbels of white lace, which remain decorative as they dry on the plant. An elegant and original ground cover to plant under trees and on the edge of woodlands, sheltered from the burning sun.

Hydrangea cordifolia belongs to the Hydrangeaceae family. It's a slow growing plant, whose vegetation can cover about 2.5m (8ft) on the soil in 10 years. An adult plant will not exceed 3m (10ft), although some branches can climb up to 80cm (32in) or 1m (3ft) in height at most. This creeping liana produces well-ramified ligneous stems, which present an interesting architecture. With age, they crack, and their bark peels off in shreds, giving the plant an attractive look even in winter. The branches cling thanks to climbing roots. Without support, the plant will form a very low, wide and dense bush. Its growth is a bit slow at the juvenile stage. The small leaves, with crenelated and dentate edges, are deciduous: they form in spring and fall in autumn. This foliage takes on a pretty golden hue at the end of the season. This hydrangea generally flowers in July, even in the shade. Its nectariferous flowers, in umbels of 10 to 12cm (4 to 5in) in diameter, are reminiscent of parasols. They are slightly domed, cream white in colour, and produce a light but sweet scent. They transform the plant into a pastoral and vaporous mass. These inflorescences do not fade, but dry slowly on the plant, adopting subtle green nuances before browning.

Hydrangea cordifolia can be used as a ground cover, to vegetate a large shaded rockery, or to dress the base of an old tree. It's a very useful plant for retaining sloping soils. It goes well with shrubby fuchsias (Fuchsia magellanica) for example, or low-maintenance plants such as Aegopodium podagraria 'Variegata', Alchemilla mollis, hostas, or Tiarella cordifolia. You can also let it run among the more classic types of hydrangea. In all cases, plant in a gently sunny to semi-shady exposure, away from burning sun, in humus-rich, moist soil.