Clematis Pruning Groups: When and How to Prune Your Climbers

Illustration of flowering clematis supported by garden trellis

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Identifying the correct clematis pruning group is essential for ensuring your climber produces a prolific display of flowers at eye level rather than becoming a tangled mass of stems with bare bases. Clematis are categorised into three primary pruning groups based on the age of the wood they flower on and the timing of their blooms. By matching your plant’s flowering habit to its group, you can determine exactly when and how much to cut back each year.

Table of Contents

Understanding the three pruning groups

The fundamental distinction between the groups is whether the plant flowers on ‘old wood’ (growth from previous seasons) or ‘new wood’ (growth produced in the current year). This determines the timing of the pruning to avoid removing the flower buds.

Pruning Group 1: Early bloomers

These plants flower in winter and spring on shoots produced during the previous summer. Because the buds for the coming year are already formed, heavy pruning in winter would remove the flowers. These typically require very little regular pruning beyond the removal of faded blooms. If an established plant needs substantial renovation, check guidance for its species first and work after flowering. Hard cutting sacrifices flowers and is not routine annual care; some large or evergreen plants need a more gradual approach.

Pruning Group 2: Large early-summer flowers

Group 2 clematis are often large-flowered cultivars that bloom in May and June on short shoots developing from the previous year’s growth. Many are ‘twice-flowering’, meaning they produce a second flush of blooms in late summer on new growth. These are pruned in February and again in early summer after the first flush of flowers. The standard method is to cut faded flowers back to a large growth bud immediately below the bloom.

Pruning Group 3: Late-summer bloomers

These plants flower from mid- to late summer on the terminal 60cm or so of the current season’s growth. Because they produce new growth from the base every year, they can be pruned hard. If left unpruned, the growth continues from the previous year’s tips, leading to flowers that are too high to see and a bare lower stem. These are best pruned back hard in February to the lowest pair of healthy buds.

Diagnosis: identifying your group by flowering time

If you have forgotten which group your clematis belongs to or the plant was not labelled, you can diagnose the group by observing when it flowers. Use the following criteria:

Flowers before June: Avoid hard winter pruning while identifying it. Early flowers alone do not separate Group 1 from a May-flowering Group 2 cultivar.
Flowers only from mid- or late summer on new shoots: This suggests Group 3. Observe a full season and check the cultivar before a hard prune.
Flowers in May/June and again in late summer: This is a Group 2 plant, requiring a two-stage pruning approach.

Practical pruning steps for established plants

Once the group is identified, follow these specific steps based on the timing of the season:

Group 1 timing and technique

When: Mid- to late spring, after flowering and once frost risk has passed.
Action: Remove faded flowers. Use thinning and training to manage the shape.

Group 2 timing and technique

When: February, and again in early summer after the first bloom.
Late-winter action: Remove dead or weak tips, working down each stem to healthy buds; retain the main living framework.
After flowering: Trim spent flowers back to a strong bud or side shoot below the bloom. Cutting all stems hard in February removes the early display.

Group 3 timing and technique

When: February or March, when buds show signs of growth.
Action: Cut all old stems back to the lowest pair of healthy buds, typically 15-30cm above soil level.

Special cases: herbaceous and hybrid clematis

Not all clematis follow the standard three-group climbing rules. Herbaceous clematis, such as C. integrifolia, C. recta, and C. heracleifolia, are non-climbing types that should be pruned to near ground level in either late autumn or early spring.

Some mid- to late summer flowering hybrids can be managed using a combination of Group 2 and Group 3 methods. This involves retaining a basic framework of stems while cutting others back to the base, which can help extend the overall flowering season. Examples of cultivars that can be treated this way include ‘Jackmanii’, ‘Perle d’Azur’, ‘Rouge Cardinal’, and ‘Star of India’.

Initial pruning for newly planted clematis

A young clematis with only one or two stems may benefit from an initial cut to encourage basal branching in its first spring. A well-branched plant with three or four healthy stems may not need it. Check the cultivar guidance, then cut just above a strong low pair of buds, commonly around 30cm above the compost or soil. Guide the resulting shoots onto the support as they extend.

Do not confuse this one-time formative treatment with the annual pruning of an established Group 1 or Group 2 plant.

Common pruning problems and diagnosis

Pruning can sometimes reveal underlying plant health issues. Be aware of the following signs:

Slime Flux: If pruned stems fail to reshoot and instead ooze a sticky, smelly substance, slime flux is one possibility; confirm against detailed symptoms before treating.
Clematis Wilt: Characterised by rapid wilting and blackening of stems, particularly in large-flowered hybrid cultivars.
Green Petal: Some plants may produce green flowers or petals, often during the first flush of the season; this is usually a temporary disorder and subsequent blooms are typically normal.

Useful products for this job

The links below open Amazon UK product searches. Check the exact item, seller, current price and compatibility before buying.

Secateurs: Essential for making clean cuts above buds and removing faded flowers without crushing the stems. Ensure blades are sharp and suitable for woody stems; bypass blades are generally preferred for live plant tissue. Search Amazon for Secateurs.
Garden Twine: Used for tying in new growth after pruning to ensure stems are spaced evenly across the support. Choose soft twine to avoid cutting into fragile clematis stems; avoid plastic twist-ties. Search Amazon for Garden Twine.

Related garden guides

Sources and further guidance

Guidance researched in September 2026. The feature image is an AI-generated illustration. Product guidance is based on published information, not hands-on testing.