How to Grow and Care for Climbing Hydrangea

Climbing hydrangea provides all of the beauty of a traditional hydrangea bush with large clusters of white flowers but in a trailing variety, adding 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. Like other hydrangea varieties, it thrives in temperate weather, partial to full sun, and acidic soil. Be careful where you plant it, as all parts of hydrangeas are toxic to dogs, cats, and horses.

Climbing Hydrangea Care

Here are the main care requirements for climbing hydrangea.

• Use a host structure that supports the weight of the plant as it climbs. These vines grow large and heavy up the sides of houses, fences, pergolas, trellises, or over the top of a garden arbor.
  
• Maintain in shrub form or use as a ground cover for a decorative way to cut down on weed growth.
• Water regularly especially in the summer.
• Maintain rich, moist soil with good drainage.
• Plant your climbing hydrangea where it will experience a range of full sun to part shade.
• Prune this vine seasonally and remove suckers. This plant takes root wherever the suckers make contact with the ground.

Light

Climbing hydrangea grows best in full sun to part shade. However, unlike other flowering vines, this hydrangea tolerates 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 slightly acidic mixture. To help maintain moisture in the soil (and to curb overwatering), add a 3-inch layer of mulch around the root zone seasonally.

Water

Like other hydrangea plants, climbing hydrangea prefers consistently moist soil. The plant needs to receive at least 1 inch of water weekly either by rain or traditional watering methods and requires more if the weather is especially hot or dry.

Temperature and Humidity

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

Fertilizer

Climbing hydrangeas are considered low-maintenance when fertilizing and do not need feeding during the first three years. After that, fertilize it in the spring before the leaves begin to bud, only if you notice issues with yellowing leaves. If so, use a 10-10-10 product just below the suggested amount on the label. In the late summer or fall, spread a 1-inch layer of compost around your plant, topped with an inch or two of mulch.

Types of Climbing Hydrangea

• "Miranda': This type has yellow and green variegated leaves. One of the more decorative varieties, Mirandas grows up to 50 feet tall and 6 feet wide.
• 'Silver Lining': This vine produces silvery-gray variegated leaves. This finicky variety prefers partial shade over full sun or full shade.
• 'Flying Saucer': This climbing hydrangea 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 bloom but it's worth the wait. Start with the largest plants possible and prune dead and damaged branches yearly. Prune in late spring or early summer after it has finished blooming.

Once the plant is established, climbing hydrangea vigorously grows. In addition to the main pruning after the bloom, you can also do some selective summer pruning if growth gets out of control.

Propagating Climbing Hydrangea

Propagate climbing hydrangea in May or June by taking a stem cutting from an established plant. Propagating an already thriving hydrangea offers a way to shape and prune your existing plant while assuring any additional vines will grow with the same look. Climbing hydrangea is simple to propagate and transplant. Here’s how:

1. Gather sharp garden shears, an alcohol wipe (to clean the shears), potting soil, rooting powder, a potting tray, clear plastic wrap, small plant stakes, and a spray bottle.
2. With disinfected shears, cut a stem 3 to 5 inches long from a healthy green branch without buds. Make your cut 2 inches below the leaf node and high enough on the stem away from the woody part.
3. Carefully remove all but the top two leaves on the cutting. If you damage the stem, discard it and start again with another cutting.
4. Prepare a potting tray with potting soil containing 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°F to 75°F. Mist the soil regularly with a spray bottle.
7. In one month, your cutting should root. At this point, expose it to the morning sun for a few weeks by bringing it outside.
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 is possible but takes patience and yields spotty results. Begin seeds in the early spring so you can transplant the seedlings into your garden bed when spring temperatures become warm:

1. Fill a pot with moist soil and place the seeds on top (not buried beneath).
2. Keep the soil moist and place your pot in a sunny window.
3. In approximately 14 days, your seeds will germinate. When you see shoots, transplant the seedlings into your garden bed.

Overwintering

Water your climbing hydrangea until the very end of the season. They require a good drenching before going dormant. Once the ground has frozen, dress the plant's base with composted manure or another organic compost mixture to provide the plant with nutrients until spring. (In warmer zones, add compost when the weather starts to cool.) Next, apply a substantial layer of hardy mulch to keep the plant's roots warm.

Common Pests & Plant Diseases

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, such as neem oil.

Climbing hydrangea faces similar issues to those of traditional hydrangea plants. Because of the density of the foliage and blooms, this variety may become afflicted with powdery mildew and leaf spot.

How to Get Climbing Hydrangea to Bloom

Climbing hydrangea plants grow very slowly and may take up to three to five years to reach the flowering stage. Once the plant is established, this eye-catching centerpiece reaches a height of 50 feet or more at maturity and produces its fragrant flowers all summer.

Bloom Months

Climbing hydrangea will begin to bloom in July and continue into the fall months. Individual blooms typically last a few weeks and are replaced with new ones during the flowering season.

What Do Climbing Hydrangea Flowers Look and Smell Like?

The lacy blooms are typically white or off-white with four petals and bloom in clusters. They have a heady, perfumy scent.

How to Encourage More Blooms

Climbing hydrangea's foliage grows abundantly long before the plant flowers. Once established, and after flowering, cut back hydrangea vines immediately before new buds appear. Pruning should occur no later than the end of June or July because new blooms 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.

Fertilizers with a high phosphorous count also help create beautiful blooms.

Common Problems With Climbing Hydrangea

Climbing hydrangea is relatively free of serious issues. If the plant is left unpruned, its vigorous growth may cause problems.

Surface Cracks

Once a mature vine has covered a surface or wall of a house, cracks in the surface may develop and become difficult to see or access for repairs.

Vines Grow Heavy

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.

Vines Grow into Gutters

Climbing hydrangea vines growing on a house without sufficient pruning may migrate into areas like gutters, making functioning roof drainage and regular maintenance a problem.