Climbing hydrangeas are gorgeous, easy to grow plants. Their climbing vines are perfect for adding some greenery to a boring wall or fence. They are versatile and will grow well under most conditions. Keep reading to find out more about these plants and how to care for one in your garden.
Key facts
| Common Names: | Climbing hydrangea |
| Botanical Name: | Hydrangea petiolaris |
| Plant Type: | Perennial, deciduous, climber |
| Sun Exposure: | Partial shade to full sun |
| Soil Type: | Fertile and moist |
| Soil pH: | Slightly acidic |
| Flowering Time: | May-July |
| Planting Time: | Spring or autumn |
| Height and Spread: | Maximum of 12m x 8m over time |
| Aspect: | North- or east-facing |
| Hardiness: | Not fully hardy |
| Difficulty: | Easy |
| Toxicity: | Toxic to humans and animals |
Caring for (Plant)
Soil
Climbing hydrangeas will thrive in moist, fertile soils. As they are often planted at the base of a wall or fence, they end up in a ‘rain shadow’, making the soil more prone to drying out. To combat this, add plenty of organic matter to the soil. This will help to retain moisture and make the soil more fertile. You should also mulch the soil annually to reduce moisture lost through evaporation. Slightly acidic soil is preferable, but not vital.
Pruning
Prune this plant in the summer when it has completely stopped flowering. The flowers will grow on last year’s shoots, so pruning straight after flowering gives the plant plenty of time to develop flowering wood. Don’t over-prune the top of the plant – this is where most of your flowers will come from. More established plants can handle hard pruning, but this can reduce flowering for the following two summers. Avoid pruning young plants, and keep your trimming light and gradual for healthy summer blooms.
Fertiliser
Climbing hydrangeas will need to be fed more regularly when they are newly-planted. Well-established plants are more self-sufficient in their nutrients, but may sometimes need a helping hand. Slow growth may be caused by lack of nutrients, but is more commonly because of dry soil, so check the moisture of the soil before feeding.
Water
When newly planted, climbing hydrangeas should be watered regularly – especially in the warmer months. Regularly check the the soil of plants in a ‘rain shadow’ to ensure they haven’t dried out too much. If you’re growing this as a potted plant, the smaller amount of soil will dry out much quicker so will need more frequent water.
Light
Climbing hydrangeas aren’t too fussy about how much light they receive. They will grow best in partial shade, with some dappled sunlight. Growing this plant in full sun is fine as long as you ensure the soil is kept moist. Also, note that the flowers may not last as long in full sun.
Direct, intense sunlight can cause scorching to the leaves. Where possible, provide some partial shade. This can either be with the positioning of the plant or with added factors such as taller planting, a canopy, or some other garden structure.
Temperature and Humidity
These plants enjoy temperatures between 15-20°C. They grow well in temperate climates, as long as conditions don’t get too hot and/or humid. Intense sun and heat can cause scorching to the leaves.
Planting Climbing Hydrangeas
In the ground
Before planting your climbing hydrangea, make sure the pot it is currently in has been watered well. This will help your plant to establish. Provide roughly a 45cm gap between the plant and the wall or fence that it is growing against. Loosen the ground with a garden fork and dig a hole the same depth as the plant’s root ball and roughly three times as wide. A good tip is to place the potted plant in the hole; the top of the pot should be flush with the top of the hole.
At this stage, mix in your compost or other organic matter. Remove your plant from its pot and place it in the hole. If the roots are over-grown or very tangled, you may need to loosen them a bit to allow for proper growth in the ground. Fill in the space around the root ball with soil. Firm it in, water the area thoroughly, and mulch the surface to help the soil retain moisture.
Potting and repotting
Climbing hydrangeas grown in containers can be potted up year-round, but it’s best to avoid doing so in the winter. The spring and summer are ideal for repotting. Make sure to use good quality potting mix to keep the soil moist and nutrient-rich. When repotting a climbing hydrangea, ensure the new pot provides at least two inches of additional room around the root ball.
Climbing Hydrangea Problem Solving
Hydrangea scale
Hydrangeas can sometimes become infested with hydrangea scale, or Pulvinaria hydrangeae. These are sap-sucking insects which can cause leaf loss and slow growth. If your plant is affected, you may notice: eggs covered with white waxy fibres; brown, oval mature scales (3mm in diameter); or pale yellow, newly-hatched insects.
To prevent this issue, regularly check young and vulnerable plants for any pests or damage. More established plants will be able to withstand small populations of hydrangea scale, but some control may be needed. For example, you can attract or introduce natural predators such as ladybirds. Pesticides are also available but can sometimes be dangerous for other insects that aren’t causing harm, so be careful when using them. In extreme cases of hydrangea scale, you may need to remove the plant entirely and place new plants in the autumn or spring.
Sparse flowers
If your climbing hydrangea is struggling to bloom, this may be a result of too much summer pruning. The flowers will be produced on the previous year’s growth, so pruning too much in the summer won’t give the plant enough time to produce flowering wood for the following year.
Other reasons for lack of flowering include:
- The plant being less than three years old
- Lack of nutrients or water
FAQs About Growing Climbing Hydrangeas
How quickly does a climbing hydrangea grow?
Their growth will be slow while they establish, but mature and settled plants can be vigorous climbers. A healthy climbing hydrangea could reach a height and spread of 12m x 8m within 15 years.
Are climbing hydrangeas deciduous?
Yes. Their leaves will turn yellow in the autumn and will shed in the winter.
Are climbing hydrangeas self clinging?
Yes. They form aerial roots that attach to walls, fences, and other structures. However, they may still require additional support.
About The Author
Belle
Belle is a horticulturalist who is passionate and knowledgeable about plants, gardening, and the environment. At work, they are a content exec and 'plant doctor', and at home they are a dedicated plant parent.
