Large-flowered clematis: when and how to prune

Large-flowered clematis: when to prune it?

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Prune in February, before the buds break. In winter the stems look dead, but they carry buds: so wait until February, even if the plant looks untidy.

Don’t know which variety you have? Look at when it flowers: if it flowers before mid-June, prune lightly; if it only flowers from July, prune hard.

On an early-flowering variety, deadhead after the first flush: a second flush often follows in late summer.

Clematis that already flower in April–May with smaller flowers, such as anemone clematis and alpine clematis, belong to a different group: prune them only after flowering, and only if needed.

What else to prune in those months? February

Large-flowered clematis: how to prune it?

1. Wear gloves: all parts are poisonous, and the sap can irritate the skin.
2. Early-flowering varieties, such as ‘Nelly Moser’ and ‘The President’: remove dead stems and lightly shorten the rest, to just above a pair of strong buds.
3. Late-flowering varieties, such as ‘Jackmanii’: cut all stems back to 20–30 cm above the ground, just above a pair of strong buds, and carefully pull the old stems out of the support.
4. In the first spring after planting, whatever the variety, cut all stems back to about 30 cm: that way the plant branches from the base.
5. In spring, tie in the new shoots every week and spread them out: they snap easily and otherwise get tangled.
6. If shoots suddenly go limp and the leaves turn black, it is clematis wilt: cut them back to healthy wood, below ground level if need be. A deeply planted clematis usually shoots again.

How much to cut, and how often?

• One prune a year at the end of winter, plus deadheading on early-flowering varieties.
• Prune early-flowering varieties lightly: cut them back hard and you lose the first flush, which comes on last year’s wood.
• If an early-flowering variety has become bare and untidy at the bottom, you can still cut it back hard every few years: you then miss the early flowers, but it flowers later in summer on the new shoots.

What does it mean for wildlife?

• Pruning in February falls outside the nesting season (15 March–15 August). A dense clematis on a wall or in a hedge does become a nesting place later in the year, though: don’t cut into it carelessly in spring and summer.
• Large-flowered varieties with open flowers and visible stamens offer pollen to honeybees, bumblebees and solitary bees from May to September.
• For wildlife, the native old man’s beard is a good choice: its fragrant white flowers attract lots of bees and hoverflies in summer, and birds nest in its tangle of stems.
• Leave a layer of mulch or low plants at the base: they keep the roots cool, and ground beetles and hedgehogs find shelter there. They also eat the slugs that attack young clematis shoots.

Common mistakes

• Cutting an early-flowering variety back hard in February, so the first flush is lost.
• Not pruning a late-flowering variety, so it only flowers at the top and goes bare at the bottom.
• Pruning in autumn or winter already, because the stems look dead.
• Working without gloves, although the sap can irritate the skin.

Nearby: related pruning guides

• Italian clematis
• Mountain clematis
• Old man’s beard
• Climbing rose
• Wisteria

Plant profile: Large-flowered clematis · Pruning calendar and basic rules