OrnamentalclimberSome care needed

Clematis

The climber most often ruined by correct-sounding pruning. Clematis fall into three groups with opposite instructions, and cutting a group 1 down in spring removes every flower for the year. The other rule worth knowing is old and reliable: head in the sun, roots in the shade.

Position: Full sun or Partial shade
Water: moderate demand
Drainage: Moisture-retentive
Grows to: 200–600 cm × 90–200 cm
Hardiness: H6
Flowers: May to September
Difficulty: Some care needed

Described view

A diagram of the three clematis pruning groups side by side, showing where each is cut and which wood carries the flowers

August

In flower

Coming next month: plant.

Clematis’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

Activity	F	M	A	M	J	J	A	S	O
Plant		March.	April.					September.	October.
In flower				May.	June.	July.	August.	September.
Prune	February.	March.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Conditions it needs

Light: Full sun, Partial shade
Frost: Very hardy
Hardiness rating: H6 (RHS)
Grows best at: 12–24 °C
Soil: Loam, Clay, Chalky
Soil pH: 6–7.5
Drainage: Moisture-retentive
Water needs: moderate
Drought: poor tolerance
Waterlogging: poor tolerance
Heat: moderate tolerance
Wind and exposure: moderate tolerance

Where these figures come from

LightSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — position
Checked 2026-08-13
FrostSourced guidancehigh confidence: Royal Horticultural Society: Clematis — hardiness
Checked 2026-08-13
Hardiness ratingSourced guidancemoderate confidence: Royal Horticultural Society: RHS hardiness ratings
Checked 2026-08-13
Grows best atSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — temperature
Checked 2026-08-13
SoilSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — soil
Checked 2026-08-13
Soil pHSourced guidancemoderate confidence: Plant Finder — Missouri Botanical Garden: Clematis — culture
Checked 2026-08-13
DrainageSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — soil
Checked 2026-08-13
Water needsHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
DroughtHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
WaterloggingHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
HeatHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Wind and exposureHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Clematis will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Works, with one condition	Clematis will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Chalky and alkaline	Works, with one condition	Clematis will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Loam	Prefers this soil	Loam suits Clematis as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Grows well here	Clematis grows perfectly well on silty without special measures, though it is not the soil it would choose.
Peaty and acid	Works, with one condition	Clematis will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Works, with one condition	Clematis will crop on shallow over rock, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Made ground and urban soil	Works, with one condition	Clematis will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height: 200–600 cm
Mature spread: 90–200 cm
Rooting depth: 60 cm
Spacing: 90–150 cm apart

Where these figures come from

Mature heightHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Mature spreadHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Rooting depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
SpacingSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — spacing
Checked 2026-08-13

Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume: 40 litres or more
Minimum depth: 45 cm

Where the container figures come from

Minimum volumeHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Minimum depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

Habit and ultimate size

What the plant becomes, rather than what it is when you buy it. The gap between the two is where most planting mistakes live.

In a container: Workable in a container, with conditions

Where these figures come from

In a containerHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

How it climbs: Tendrils or leaf stalks — needs mesh or wire to grip
Vigour: Vigorous — needs a substantial support and annual attention

Where these figures come from

How it climbsSourced guidancehigh confidence: Royal Horticultural Society: Clematis — support
Checked 2026-08-13
VigourSourced guidancemoderate confidence: Royal Horticultural Society: Clematis — vigour
Checked 2026-08-13

Support it needs. Climbs by twisting its leaf stalks around thin supports, so it needs wire, mesh or twiggy growth no thicker than a pencil. It cannot grip a flat trellis slat or a bare wall, and a plant sold as a wall climber with nothing to hold will simply lie on the ground.

Pruning group. Group 1 flowers on last year's wood and is barely pruned; Group 2 flowers on both and is tidied lightly in spring; Group 3 flowers on new growth and is cut to about 30 cm every spring. Pruning a Group 1 as though it were a Group 3 removes every flower for the year, which is the commonest clematis disappointment there is.

source

Sourced guidancehigh confidence

Royal Horticultural Society: Clematis — pruning group

Checked 2026-08-13

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

Method	Suitability	What it needs
Open ground	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Traditional dug bed	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Raised bed	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Container	Workable source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13	40 litres; Compact cultivars; Shade over the pot
Hydroponics	Not suitable source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13

Growing it

PruningEstablish the pruning group before cutting anything. Group 1 flowers on last year's wood and is pruned lightly after flowering; group 2 flowers on both and gets a light tidy in spring; group 3 flowers on new growth and is cut to about 30 cm in late winter. Pruning a group 1 as though it were a group 3 removes the entire year's flowers, and it is the commonest clematis mistake.
MulchingShade the root run with a slab, a mulch or a low planting. Clematis want cool moist roots and a sunny top, and a hot dry root run is behind much of the wilting and poor flowering blamed on disease.
WateringWater deeply and thoroughly rather than often, and keep doing it for the first two or three years — clematis are deep-rooted and slow to establish, and the usual reason one sits and sulks is that it was watered lightly at the surface. A can or two poured slowly at the base once a week in a dry spell is worth far more than a daily sprinkle. Plant it 30–45 cm out from a wall, where the soil is not in the wall's rain shadow, and keep the root area shaded and cool with a mulch, a paving slab or a low plant in front — hot dry roots are the standard cause of a clematis that wilts and disappoints.
FeedingFeed in spring as growth starts, with a balanced or rose-type fertiliser, and follow with a high-potash liquid feed every couple of weeks through the growing season on a plant you want a lot of flower from. Stop once it is in full flower and do not feed in autumn. Clematis are genuinely hungry compared with most climbers, and a plant that flowers thinly at the top with bare stems below is more often short of feed, water and correct pruning together than of any one of them — the pruning group is what decides which stems carry flowers, and no feeding regime compensates for cutting the wrong ones.

Where this guidance comes from

PruningSourced guidancehigh confidence: Royal Horticultural Society: Clematis — pruning groups
Checked 2026-08-13
MulchingSourced guidancehigh confidence: Royal Horticultural Society: Clematis — planting
Checked 2026-08-13
WateringSourced guidancehigh confidence: Royal Horticultural Society: Clematis — cultivation
Checked 2026-08-13
FeedingSourced guidancehigh confidence: Royal Horticultural Society: Clematis — cultivation
Checked 2026-08-13

The bud you cut to becomes the new shoot, and it grows in the direction it points — which is why an outward-facing bud opens the plant up and an inward-facing one crosses the middle.

What goes wrong

Problem	How often	Notes
Clematis wilt	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Dead top, live roots. Cut below the lesion and a deep-planted clematis usually regrows.
Pruned at the wrong time	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	The pruning group is the whole answer: group 1 and 2 flower on last year's wood.
Slugs and snails	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	New shoots at ground level are very vulnerable in spring.

Start from what you can see

Healthy growth but no flowers

Sources for this page

GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.

If something is wrong with it

Plant wilting although the soil is moist — 2 causes GrowingHQ holds for clematis

Something else? Work through it with the diagnostic tool.