Climbing Hydrangea

The Climbing Hydrangea (Hydrangea petiolaris) belongs to the family of Hydrangeas (Hydrangeaceae), it grows on walls and facades, Pergolas as well as fences and enhances your garden with its fine white inflorescences. It originates from the forests of Japan and Taiwan and Korea. The decorative climbing shrub is hardy and easy to care for.

The shoots of the Climbing Hydrangea form aerial rootlets on the side facing away from the light, which then develop into thicker branches. The bark is reddish-brown and flakes off older branches. Climbing Hydrangeas can reach up to a height of 49.2 feet on trellis, walls and facades, however, at first, they are slow-growing. Without a climbing aid, the Climbing Hydrangea grows into a hemispherical and wide shrub and can also serve as a ground cover.

The leaves of the climbing Hydrangea are glossy green in color, oval to round in shape and approximately 3.93 inches long. They sit on long petioles and turn bright yellow in autumn. Some varieties retain the green leaves in mild winters and remain on the shoots until next spring.

The sweet smelling flowers appear from May to July. They are flat and have inflorescences up to 9.84 inches wide. The corymbs have a wreath of sterile white flowers on the outside. The inner flowers are fertile and have no petals. Climbing Hydrangeas only bloom after about five years of no blooming.

The Climbing Hydrangea thrives on permeable and humus-rich soils in partially shaded to fully-shaded locations that are cool and humid. The plants do not tolerate calcareous soil and are sensitive to soil compaction.

Climbing Hydrangeas need slightly acidic to acidic soil, so you should put some Rhododendron soil in the planting pit. Best time to plant is from March to mid-May. The planting pit should be about twice as big as the root ball. Loosen it up a bit and water it well after planting. You must also soak dry pot balls in a bucket of water for a few minutes before planting. A layer of mulch around the Climbing Hydrangea keeps the soil evenly moist.

Similar to the Ivy plant, Climbing Hydrangeas look for anchors on bare walls, as long as they are not too smooth. This is possible thanks to special aerial rootlets. In the case of young plants, a climbing aid is still a good choice to guide the shoots upwards and to support growth. On a wall or fence, you should pin the branches with wires. Climbing Hydrangeas need sufficient water and should be kept evenly moist, but waterlogging should be avoided. You can fertilize it in spring, spread leaf compost enriched with horn manure and Rhododendron fertilizer.

Climbing Hydrangeas can be pruned, but as a rule they do not need to be pruned if the plants have enough space to spread out. If necessary, you can shorten the shoots of young climbing Hydrangeas by about a third immediately after planting to stimulate branching. With older plants, pruning into perennial wood is also possible without problems. February and March months are ideal for pruning.

Climbing Hydrangeas are suitable as decorative climbing plants on Creepers walls, pergolas and fences. This is when their inflorescences and foliage ornamentation shine out. Together with Clematis, the Climbing Hydrangeas form a beautiful picture on a wall or facade.

‘Semiola’ is a new breed with white flowers that keeps its green foliage in mild winters. Copper-red shoots show up in spring and can reach heights of up to 3.28 yards. It also climbs without a climbing aid and can serve as an attractive ground cover.
"Silver lining" is also often wintergreen. The variety has fine, white-green variegated leaves and is also suitable as a container plant on the balcony.
‘Miranda’ blooms in creamy white flowers with large yellow-green leaves.

Climbing Hydrangeas can be propagated very easily from spring to early summer by placing side shoots close to the ground. Remove the leaves from the mid section of the shoots and with a pocket knife make a wound cut by lifting off a narrow strip of bark on the underside of the shoot. Then dig the middle shoot segment lightly into humus-rich soil and fix it if necessary, and keep the soil evenly moist. During the season, the offshoot takes root and can then be separated from the mother plant and transplanted in fall or spring.

If you want a larger number of offspring, climbing Hydrangeas can also be grown from cuttings. The young, slightly woody and flowerless shoots are best suited for planting in June and July. The cultivation method is otherwise the same as that of propagating cuttings from bigleaf Hydrangeas Alternatively, in winter it is also possible to grow from unrooted cuttings — hardwood cuttings.

Climbing Hydrangeas are robust climbing plants that are rarely attacked by diseases or pests. At times it is possible for chlorosis to occur. Then the leaves turn yellow and have green veins running through them. A dose of Rhododendron soil or peat can prevent this. Powdery mildew or downy mildew also occur occasionally.