Climbing hydrangeas feature large, fragrant clusters of white flowers that bloom in late spring and summer against a backdrop of dark green, heart-shaped foliage. These massive vines readily climb columns, trees, and other supporting structures. A climbing hydrangea plant grows 30 to 80 feet (9-24 m.) tall, but it tolerates pruning to shorter heights. You can also grow it as a shrub.
I. Appearance and Characteristics
Hydrangea anomala, the Japanese climbing-hydrangea, is a species of flowering plant in the family Hydrangeaceae native to the woodlands of the Himalaya, southern and central China and northern Myanmar.
‘Hydrangea’ is derived from Greek and means ‘water vessel’, which is in reference to the shape of its seed capsules.
‘Anomala’ means ‘anomalous’ or ‘unlike its fellows’.
It is a woody climbing plant, growing to 12 m height up trees or rock faces, climbing by means of small aerial roots on the stems. The leaves are deciduous, ovate, 7–13 cm long and 4–10 cm broad, with a heart-shaped base, coarsely serrated margin and acute apex. The flowers are produced in flat corymbs 5–15 cm diameter in mid-summer; each corymb includes a small number of peripheral sterile white flowers 2–3.5 cm across, and numerous small, creamy-white fertile flowers 1–2 mm diameter. The fruit is a dry urn-shaped capsule 3–5 mm diameter containing several small winged seeds.
The closely related Hydrangea petiolaris from eastern Siberia, Japan, and Korea, is sometimes treated as a subspecies of H. anomala; it differs in growing larger (to 20 m) and flower corymbs up to 25 cm diameter. The common name Climbing hydrangea is applied to both species.
II. How to Grow and Care
Sunlight
Climbing hydrangea is one of the few hardy flowering vines that tolerate shade. In hot climates, choose a location where the plant will get dappled sunlight or partial shade. In the cooler regions of the South, the vine can do well with lots of morning sunshine if adequately watered. Climbing hydrangeas that do get more sun tend to bloom better.
Temperature and Humidity
This plant is hardy in USDA plant zones 4 through 8. Climbing hydrangea does well in temperate climates but may wilt in hot, humid conditions. It also can be damaged by sunburn, so it may not be the best choice if you experience scorching summers.
Watering
As with other hydrangea plants, this species likes consistently moist soil. Place it where it will get watered about 1 inch weekly, or even more often in hot weather. Interesting side note about the word hydrangea: the Greek root hydra refers to water, and angeon comes from the Greek for “vessel.”
Soil
Climbing hydrangea needs a rich, moist, well-drained soil. If your soil needs improvement, mix in a generous amount of compost before planting. Apply a 3-inch layer of mulch to help retain water in the soil around the root zone and reduce weeds.
Fertilizing
Fertilize this plant in the spring before the leaves begin to bud. Granular fertilizer with a high phosphorous count will encourage beautiful blooms. Fertilize again after the flowers have bloomed in the summer.
Pruning
Newly planted climbing hydrangea vines are slow to grow and slow to bloom, but it’s worth the wait for the years of enjoyment they bring. Start with the largest plants possible and prune only the dead and damaged branches each year, in late spring or early summer. Once the plant is established, climbing hydrangea grows vigorously and may need summer pruning or shaping to your liking.
Cutting and drying hydrangea flower heads is a favorite pastime for seasoned gardeners. Once dry, climbing hydrangea flowers turn reddish-brown, and the heads can be used in crafts, dried bouquets, or incorporated into a dried arrangement for the home.
Propagation
Climbing hydrangea can be propagated by cuttings. Do this in the spring, when the plant has sent out new, tender growth, by following these steps:
- Fill a seed tray with light potting soil or seed-starting soil and moisten the soil.
- Sanitize a sharp pair of pruning shears with alcohol.
- Select a green stem and cut sections that are 3 to 5 inches long, taking care to keep track of which end was pointing up.
- Remove all but the top pair of leaves from each cutting.
- Dip each cutting in rooting powder, then stick the bottom of the stem an inch or two into the soil of your seed tray.
- Cover the tray with a clear plastic dome or piece of plastic and place in a warm spot in indirect light.
- Mist regularly with a spray bottle to keep the soil from drying out. The cuttings should root in about a month, at which point you can transfer them to individual pots and gradually expose them to the outdoors.
Hydrangeas can also be propagated by layering in the spring, as long as you have a young, healthy branch that is close to the ground:
- Gently pull a green stem down to the ground. Take a sharp, clean knife and nick the bark on the bottom of the stem where it meets the soil.
- Remove any leaves in the area where the stem is in contact with the soil.
- Use a hooked wire or landscape staple to pin the spot that you nicked tightly to the soil.
- Place a brick or stone on top of the stem. Keep an eye on soil moisture and water when dry.
- Once the stem has rooted, you can cut it from the mother plant just behind the roots. Leave the severed stem undisturbed for a week before digging it up and transplanting it.
Pests and Diseases
Common Pests & Plant Diseases
Climbing hydrangea faces similar issues to those of traditional hydrangea plants. Because of the density of the foliage and blooms, this variety can become afflicted with mildew and leaf spot. As for pests, you may spot signs of spider mites, scale, and aphids, all of which can be treated with a mild insecticide or, a non-toxic alternative, neem oil.
Common Problems
Once a mature vine has covered a surface, cracks in the surface can develop and become difficult to see or access for repairs. Also, the weight of the vines may loosen surfaces like shingles, siding, and clapboard, and you won’t be able to access the surface to paint it without massive pruning. Lastly, vines on a house without sufficient pruning may also grow into areas like gutters, making regular maintenance a problem.
How To Get Climbing Hydrangea To Bloom
Climbing hydrangeas can take a few seasons or even a few years to get settled in and begin blooming in late spring or summer. Be careful not to prune the vine in fall, winter, or spring, as you may remove flower buds. Your hydrangea will set buds only if there are six weeks of temperatures below 65 degrees. A sudden frost can damage flower buds that are about to open. If your hydrangea is on the verge of blooming, cover it with a blanket or tarp until the cold snap passes.
III. Types of Climbing Hydrangea
- Hydrangea anomala is the most common variety of climbing hydrangea. It yields white flowers and has excellent frost and heat tolerance.
- The Miranda variety has variegated leaves that are part yellow and part green. One of the more decorative varieties, Mirandas can grow up to 50 feet tall and six feet wide.
- The Silver Lining climbing hydrangea produces silvery-grey variegated leaves. This variety is finicky, however, preferring partial shade over full sun or full shade.
- The Flying Saucer variety is known for its inflorescences that resemble flying saucers. These showy white blooms look fabulous against their backdrop of bright green foliage.
Find Where to Buy the Best Climbing Hydrangea (Hydrangea anomala)
[content-egg-block template=offers_logo_shipping cols_order=3,2,1,5,4 hide=badge visible=number border_color=info limit=8]