Photo: Salicyna, CC BY-SA 4.0 · source
Pruning guide · Climber
Climbing hydrangea: when and how to prune
Hydrangea anomala subsp. petiolaris
Prune a climbing hydrangea after flowering, in July–August, and only lightly: cut back branches that stick out too far from the wall or grow towards gutters and windows.
The climbing hydrangea clings to a wall or tree trunk with short aerial roots, up to 10–15 m high, and is one of the few flowering climbers for a shady north wall. It flowers in June–July on short side shoots on older wood. Prune in winter or spring and you cut those flowers off. It needs little pruning: keeping it within the wall and removing an old stem now and then is enough.
| Pruning months | July–August |
|---|---|
| Nesting season (15 March–15 August) | Take care in July–August |
| Flowering | June–July |
| Good for bees, butterflies and birds | Yes, for bees and birds |
| Native to Belgium | No, planted |
Climbing hydrangea: when to prune it?
Prune after flowering, in July–August. It then has the rest of the summer to make new side shoots that will flower next year.
Don’t prune in winter or spring: you would cut off the short flowering shoots.
Rejuvenate a plant that has grown too thick and heavy after flowering too, but spread over a few years.
Climbing hydrangea: how to prune it?
- Cut branches that stick out too far from the wall back to a side branch close to the wall.
- Cut away everything growing towards gutters, downpipes, windows and roof tiles, far enough back to stay clear for a year.
- Leave the short side shoots along the wall: that is where it will flower next year.
- Rejuvenate a plant that is too thick by removing a few of the oldest stems at the base each time, spread over a few years.
- Cut off the faded flower heads if you don’t like them; in winter the dry heads are decorative too.
How much to cut, and how often?
- Little: each year whatever sticks out or is in the way.
- An old, heavy plant: a few old stems every few years.
What does it mean for wildlife?
- July and early August fall in the nesting season (until 15 August). Blackbirds, robins, wrens and sometimes spotted flycatchers nest in a dense climbing hydrangea on a wall: look carefully first, and ideally prune after mid-August.
- The flat flower heads have small, fertile flowers in the centre that attract bees, hoverflies and beetles. The large white outer flowers are only there to lure them.
- A planted north wall shelters insects and spiders all year round, food for birds.
- It is a non-native, but it doesn’t run wild. If you also want a native climber for shade, choose ivy.
Common mistakes
- Pruning in winter or spring, so the flowering is lost.
- Letting it grow into the gutter and under the roof tiles.
- Cutting an old plant back hard in one go, so it doesn’t flower for years.
- Pruning without first checking for nests.
Caution: Before you prune, check that no birds are nesting in the dense climber.
Nearby: related pruning guides
Similar to: Difference from hydrangea · Difference from common ivy
Plant profile: Climbing hydrangea · Pruning calendar and basic rules