Bare walls, bare house walls and other unsightly corners in the garden can be beautifully greened with the help of a climbing hydrangea. Within a few years, a single small bush develops into a climbing plant up to 15 meters high and five meters wide, which not only makes gray concrete disappear behind a dense green wall: the creamy white, sweet-smelling plate flowers also attract numerous insects, especially butterflies, an.
How do I care for climbing hydrangeas in the garden?
Climbing hydrangeas require a partially shaded to shady location, fresh to moist soil with acidic to neutral pH, regular watering without waterlogging and occasional pruning. Young plants benefit from climbing aid and light winter protection.
Origin and distribution
The lushly growing climbing hydrangea (bot. Hydrangea petiolaris) is at home in the shady and moist cloud forests of Japan, Korea and Taiwan. However, the species from the hydrangea family (bot. Hydrangeaceae) has been planted in other parts of the world for many decades and is primarily used as decorative greenery on facades, walls, fences or pergolas.
Usage
As the name suggests, the climbing hydrangea is a self-climbing climbing plant that is mainly used to green walls, walls, fences and pergolas. When kept in this position, the strong green leaves and the numerous, creamy white plate flowers come into their own wonderfully. Climbing hydrangeas work best when planted solitary, especially since the species takes up a lot of space. Alternatively, planting together with the clematis is possible, which requires similar growth and location conditions and whose colored flowers provide a nice complement to the white and green colors of the climbing hydrangea.
Appearance and growth
The climbing hydrangea develops its sprouting roots exclusively on the side facing away from the light of its numerous shoots, which can develop into thick branches over time. With the help of these climbing roots, the self-climber reaches heights of an average of six to seven meters, but can grow up to 15 meters high under favorable conditions. However, it will take a while until then, because with around 15 to 20 centimeters of new growth per year, the plant is one of the slow-growing species - although the speed can definitely be increased in a suitable location and in mild winters.
In the first few years, the climbing hydrangea should receive a climbing aid in order to find proper support on walls, walls or fences. But be careful: plastered surfaces and concrete walls, such as those common to house walls, can be severely damaged by penetrating roots. Therefore, the climbing frame should be installed at a distance of around ten centimeters from the wall. Solid stone walls, on the other hand, are not at risk.
If there is no climbing opportunity, the species develops into a hemispherical and wide shrub up to two meters high. Typically, the reddish-brown bark peels off on older branches and twigs - so it is not, as is often assumed, a symptom of a disease or pest infestation.
leaves
The glossy green leaves of the climbing hydrangea are very similar to those of the related garden hydrangea: They are long-stemmed, have an ovoid to rounded shape and can be up to ten centimeters long. The species is deciduous, and the foliage of most varieties turns bright yellow in autumn. However, some newer varieties are now considered evergreen and retain their dense foliage even during the winter. This variety only sheds this next spring before the new shoots.
Flowers and flowering time
Don't be surprised if your climbing hydrangea, which was planted just a few months ago, doesn't want to bloom yet: This behavior is completely normal, as the species only reaches its flat, up to 1,000 mts for the first time after it has been standing for at least five to eight years 25 centimeter wide umbrella panicles. These consist of the inconspicuous, fertile inner flowers and a wreath of creamy white, sterile show flowers. The numerous, sweet-smelling flower plates appear between May and July and serve as valuable pasture for numerous insects - especially butterflies, bees and bumblebees. Capsule fruits then form.
Toxicity
Like all hydrangeas, the climbing hydrangea is poisonous, especially for pets such as dogs, cats, small rodents and birds. Make sure that your pets do not eat the plant, as the toxins it contains can cause stomach and intestinal problems and circulatory disorders. Small children are also at risk.
Which location is suitable?
The climbing hydrangea is the right plant for semi-shady to shady locations and also perfectly greens north faces, for example. The forest plant does not tolerate direct sunlight as this would burn both the leaves and the flowers. A place protected from the wind is also important. In principle, it is also possible to keep them in a sufficiently large container on the balcony or terrace, but you should be careful in rented apartments: the cultivation of self-climbing climbing plants is often prohibited here, as the adhesive roots can cause damage to the plaster and walls.
Floor
In addition to a semi-shady to shady spot in the garden, the climbing hydrangea also needs fresh to moist soil with an acidic to neutral pH value. But be careful: Although the plant feels comfortable on a fresh surface - which should generally be moister the brighter the climbing hydrangea is - it still cannot tolerate waterlogging. Therefore, if possible, do not plant the species at the foot of a slope or in a depression - this is where the water collects and eventually causes rot diseases. Also avoid calcareous soil - for example along the plastered wall of a house - as the plant is not tolerant of lime.
Planting climbing hydrangeas correctly
The best time to plant climbing hydrangea is a mild day between the end of March and the end of May. Dip the dry root ball in a bucket of water so that the fine roots can soak up moisture. In the meantime, dig a generously sized planting hole that should be about twice as wide and deep as the root ball. Lightly loosen the side walls and the soil and mix the excavated soil with compost and/or rhododendron soil. Now plant the climbing hydrangea, water it well and then mulch the root area. The mulch layer prevents the soil from drying out and thus helps the plant to take root.
Although the climbing hydrangea develops self-adhering climbing roots with which it can climb surfaces that are not too smooth - similar to ivy - it benefits from support in the form of a trellis or climbing aid when it is young. You can use this to direct the fresh shoots in the desired direction or keep the plant away from plastered or otherwise porous surfaces. The branches can be attached to a fence or pergola using flower wires.
Watering and fertilizing
Climbing hydrangeas require a lot of water and should therefore be kept evenly moist - waterlogging, on the other hand, should be avoided, which is why planting on compacted soils should only be done with additional drainage. If the substrate is too dry, the plant will drop leaves and flowers. In spring, provide the plant with ripe leaf compost and horn meal (€6.00 on Amazon) or shavings. If necessary (e.g. lack of growth or chlorosis), you can also fertilize with hydrangea or rhododendron fertilizer. Fertilization with blue grain, which is often used by gardeners, is not advisable.
Cut climbing hydrangeas correctly
Especially young specimens of the climbing hydrangea do not need pruning as they grow very slowly anyway. However, you can cut back the shoots by about a third immediately after planting to achieve stronger branching. For older plants, it is best to proceed as follows:
- lightening if necessary
- remove dried, dead and frozen branches at the base
- cut these in spring
- otherwise cut climbing hydrangea immediately after flowering
- because the flowers of the following year are already formed in autumn
- Use sharp and clean garden or rose scissors
- always cut just above a bud
- Cuts into perennial wood are possible
- Observe growth behavior and cut back if necessary
- e.g. when the plant threatens to overgrow the window
If possible, plant the climbing hydrangea in such a way that the plant can spread according to its nature and does not have to be limited in its growth by frequent pruning.read more
Propagate climbing hydrangeas
In early summer, climbing hydrangeas can be propagated very well using cuttings or ground-level sinkers (which are only cut from the mother plant after successful rooting), for which you only cut slightly woody, young and flowerless branches between June and July. Plant them individually in pots with potting soil and keep the substrate slightly moist. Alternatively, propagation is possible using so-called cuttings, which are cut in winter.read more
Wintering
Climbing hydrangeas are hardy and only require light winter protection as freshly planted young plants, for example in the form of a cover with brushwood or jute.
Diseases and pests
No plant is completely immune to diseases, including the otherwise very robust climbing hydrangea. Mildew diseases in particular cause problems for it, and chlorosis also develops quickly in locations with a pH value that is too high. When it comes to pests, the main ones are aphids.
Tip
The climbing hydrangea can also be planted very well as a ground cover, but be careful: the plant uses every opportunity to grow upwards.
Species and varieties
There are a number of attractive cultivars of the Hydrangea petiolaris species, but they are particularly widespread in Great Britain. In this country it is mainly this species that is planted, but with a bit of luck you can sometimes find pretty varieties such as:
- 'Cordifolia': dwarf form that only grows up to three meters high with creamy white flowers
- 'Miranda': striking yellow-green variegated foliage, large, creamy white flowers
- 'Semiola': new evergreen variety with beautiful, white flowers
- 'Silver Lining': low-growing variety with a maximum height of two meters and striking white-green variegated foliage, very suitable for container planting
In addition to the climbing hydrangea Hydrangea petiolaris, the closely related and quite similar-looking false or split hydrangea (bot. Schizophragma hydrangeoides) is also often planted in the garden.
