How to Grow and Care for Climbing Hydrangea

Climbing hydrangea (Hydrangea anomala) provides all of the beauty of a traditional hydrangea bush, but in a trailing variety used to add visual interest to walls or fences. Native to Asia, this hydrangea species is a flowering deciduous vine best planted or transplanted in the late spring. In summer, white lacy blooms cap the lush green ovate leaves. A true climber, Hydrangea anomala has holdfasts (suckers) on its branches, allowing it to scale structures without the use of a trellis.

Climbing hydrangea plants grow very slowly and may take up to three to five years just to reach the flowering stage. That said, once the plant is established, this eye-catching centerpiece can reach a height of 50 feet or more at maturity and produce its fragrant flowers all summer long. Be careful where you plant it, as all parts of hydrangeas are toxic to dogs, cats, and horses.

Climbing Hydrangea Care

Hydrangea vines are often trained to grow up the sides of houses, fences, pergolas, trellises, or over the top of a garden arbor. Because the vines grow large and heavy, it's important to make sure that the host structure can support the plant's weight, and that you prune it seasonally.

Climbing hydrangea can also be maintained in shrub form or used as a ground cover, as it takes root wherever the suckers make contact with the ground. Cultivating the plant in this way makes for a decorative garden floor and also cuts down on weed growth.

Light

Climbing hydrangea grows best in full sun to part shade. However, unlike other flowering vines, this variety can tolerate quite a bit of shade, especially in hot climates where they prefer at least partial (or even full) shade at some point in the day. In sunny regions, make sure your plant is consistently and adequately watered. Any hydrangea exposed to full sun will bloom more vibrantly and fully than one that experiences a lot of shade.

Soil

Plant your climbing hydrangea in garden beds that contain rich, moist soil with good drainage. Depleted beds may need amending with nutrient-dense compost before planting or transplanting. Climbing hydrangea isn't particular about its soil pH level but will grow and bloom best in a mixture that is slightly acidic. To help maintain moisture in the soil (and to curb overwatering), maintain a three-inch layer of mulch around the root zone seasonally.

Water

Similar to other hydrangea plants, climbing hydrangea likes the soil to be consistently moist. The Greek root hydr- in the name refers to "water," while angeon comes from the Greek word "vessel." The plant needs to receive at least one inch of water weekly either by rain or traditional watering methods and can sometimes require more if the weather is especially hot or dry.

Temperature and Humidity

Climbing hydrangea plants do well in temperate climates, but they don't like hot and humid conditions. The plant can be damaged easily by intense sun and prefers daytime temperatures that hover around 70 degrees F, and night temperatures around 60 degrees F. Additionally, climbing hydrangea vines will only set buds if they experience at least six weeks of temperatures below 65 degrees F. A sudden frost can damage buds, impeding your plant's flowering the following year.

Fertilizer

Climbing hydrangeas are considered "low-maintenance" when it comes to fertilizing. You can usually just let your plant be for the first three years. After that, fertilize it in the spring before the leaves begin to bud, only if you are noticing issues with yellowing leaves. If so, use a 10-10-10 product just below the suggested amount on the label. Fertilizer with a high phosphorous count will also help create beautiful blooms. In the late summer or fall, make sure to spread a one-inch layer of compost around your plant, topped with an inch or two of mulch.

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.

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 flowerheads 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.

Propagating Climbing Hydrangea

Propagate climbing hydrangea in May or June by taking a cutting from the stem of an established plant. Propagating an already thriving hydrangea offers a way to shape and prune your existing garden treasure, while also assuring any additional plants will maintain the same look. Climbing hydrangea is simple to propagate and transplant with a few trusty supplies. Here’s how:

1. Gather your sharp garden shears, an alcohol wipe, potting soil, rooting powder, a potting tray, clear plastic wrap, small plant stakes, and a spray bottle.
2. Wipe your shear blades with alcohol. Select a healthy green stem without buds. Cut a stem three to five inches long, making your cut two inches below the leaf node and high enough on the stem so that you don't encounter the woody part.
3. Use your shears to carefully remove all but the top two leaves on the cutting. If you damage the stem, discard it and start over with another cutting.
4. Prepare a potting tray with potting soil that contains a mixture of loam and perlite.
5. Dip the end of your cutting in your rooting powder and stick it into a prepared hole in the moist soil.
6. Cover your planting with plastic wrap or a plastic bag, and use plant stakes to support it. Place your tray in an area that receives low light and maintains a stable temperature of 70 to 75 degrees F. Mist the soil regularly with a spray bottle.
7. In one month, your cutting should begin to root. At this point, expose it to the morning sun for a few weeks by taking it outside, and then bringing it back in.
8. Plant your cutting in your garden bed in the spring, once temperatures have warmed.

How to Grow Climbing Hydrangea From Seed

Growing climbing hydrangea from seed involves filling a pot with soil and placing the seeds on top (not buried beneath). Keep the soil moist and place your pot in a sunny window. In approximately 14 days, your seeds will germinate. When you begin to see shoots, it's safe to transplant your seedling into your garden bed when spring temperatures become warm.

Overwintering

Make sure to water your climbing hydrangea up until the bitter end of the season. These plants need a good drenching before going to sleep for winter. Once the ground has frozen, dress the base of the plant with manure or another organic compost mixture to provide the plant with nutrients come spring. (In warmer zones, you can add compost when the weather starts to cool.) Next, apply a substantial layer of hardy mulch to keep the plant's roots warm. Decorative mulch will work, as will straw, hay, or fallen leaves.

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.

How to Get Climbing Hydrangea to Bloom

Climbing hydrangea is an exercise in patience, as the foliage will grow with abundance long before the plant flowers. Once established, assure summer blooms by pruning your hydrangea in late June or July, as new blooms will develop on the prior year's branches. Cutting in the fall, winter, or spring may cause you to snip off buds before they would otherwise flower.

Common Problems With Climbing Hydrangea

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.