6 Clematis Cultivars from Taylors for North-Facing Pergolas

Why a north aspect changes the cultivar shortlist

North-facing structures stay cool and damp at the root zone, which suits clematis far better than the hot, dry footings of a south wall. The species that struggle here are the large-flowered early hybrids bred for full sun. What performs instead are the montana types, the alpina and macropetala groups, and a handful of viticella selections that tolerate dappled light. Taylors splits its catalogue by pruning group, and on a north aspect the Group 1 and Group 3 plants do most of the work.

The limiting factor is not cold but accumulated light over the growing season. A plant on the north side of a 2.4 metre pergola in central England banks roughly half the photons its south-side equivalent does. That shifts flowering later by ten to fourteen days and reduces stem density. Choosing cultivars already adapted to woodland-edge conditions in the wild removes most of the disappointment. The six below are all listed by Taylors as suitable for shade or partial shade, and all have held up on cool aspects in trial gardens.

The six cultivars, by pruning group

Clematis alpina Frances Rivis opens nodding blue-violet bells in April before most other climbers have broken bud. It belongs to Group 1, so it flowers on the previous year’s wood and needs no annual hard cut. On a north pergola it will reach 2.5 to 3 metres and tolerate the low spring light because it evolved in alpine scrub.

Clematis macropetala Markham’s Pink carries semi-double pink flowers in late April and May, again on old wood, Group 1. It is among the most shade-forgiving in the Taylors range and rarely exceeds 3 metres, which keeps it inside the frame of a domestic pergola.

Clematis montana Elizabeth is the vigorous choice, vanilla-scented soft pink, capable of 7 metres if unchecked. Group 1, it flowers in May on growth made the previous summer. On a north aspect its vigour is an advantage because the plant fills the structure even with reduced light, though it needs space and a sturdy frame.

Clematis Etoile Violette is a viticella, Group 3, cut back hard each February to about 30 centimetres. It produces masses of deep purple four-petalled flowers from July to September and shrugs off the cool aspect that defeats large-flowered hybrids. Expect 3 to 4 metres of new growth each year.

Clematis Polish Spirit is another reliable viticella, Group 3, rich violet-purple, flowering July into October. It carries more flowers per stem than most viticellas and resists clematis wilt, which matters on damp north-facing soil where wilt pressure is higher.

Clematis Alba Luxurians completes the set, a viticella with white flowers tipped green, Group 3, flowering late summer. The green tips are most pronounced in cooler, shadier positions, so the north aspect actually intensifies the feature that makes the cultivar distinctive.

Espalier training against the uprights

Clematis do not self-cling. They climb by twisting leaf petioles around supports no thicker than 4 to 5 millimetres, so a bare pergola post gives them nothing to grip. Espalier training solves this by fixing a grid the petioles can reach. Stretch galvanised wire horizontally at 30 centimetre intervals up each upright, tensioned with vine eyes screwed into the timber, then run a few verticals to make a mesh.

For the Group 1 montana and alpina types, tie in the leading shoots fanwise as they extend, spacing them 15 to 20 centimetres apart so each gets light. These plants flower on old wood, so the framework you build in year one becomes the flowering structure for years two and three. Cut nothing back hard. After flowering, shorten only the shoots that have outgrown the frame.

Group 3 viticellas are simpler because the whole top is removed each February. Train the season’s new growth horizontally where you can, since clematis flower more freely on stems bent toward the horizontal than on vertical leaders. Soft fillis twine or thin garden wire works for tying in. Check ties every few weeks during the May to July growth surge, when a viticella can add 30 centimetres of stem in a week and strangle itself on an old tie.

Dalefoot wool compost for the first season

Dalefoot Composts, made in Cumbria from sheep’s wool and bracken, holds water better than most peat-free mixes and releases nitrogen slowly as the wool breaks down. For clematis seedlings or young plants potted on from a 9 centimetre pot, the Dalefoot seed compost or the general-purpose blend suits the first season well because clematis roots resent drying out.

Pot young plants deep. Set the crown 5 to 8 centimetres below the surface, which encourages basal shoots and gives the plant a reserve of buds below ground if the top is damaged by wilt. Fill around the rootball with the wool compost firmed gently, water in, and keep the pot in light shade until established. The wool content means you can water less often than with a bark-based mix, which matters because overwatering a clematis in a free-draining bark compost is a common cause of early collapse. By midsummer the slow nitrogen release from the wool will have driven a strong flush of growth without the salt spike a synthetic feed can cause in a small pot.

Comfrey liquid feed for the flowering push

Comfrey leaves contain a high ratio of potassium to nitrogen, which favours flower production over leaf growth, and that suits clematis once they are climbing. Cut Bocking 14 comfrey, a sterile cultivar that will not seed itself across the garden, and pack the leaves into a lidded bucket or a length of downpipe with a cap.

Two methods work. Water-steeped: submerge the leaves, weight them down, and draw off the dark liquid after four to six weeks, diluting it 1 part feed to 10 parts water before applying. Concentrate: pack leaves dry with no water, let them rot down under a weighted board, and collect the thick black liquor that drains out, diluting that 1 to 15 because it is far stronger. The steeped version smells worse but is ready sooner.

Apply the diluted feed to clematis from late May, when buds are forming, through to the end of flowering, about once a fortnight. The Group 3 viticellas respond most visibly because they build their entire flowering canopy in a single season and draw heavily on potassium to do it. Stop feeding by early autumn so the plant hardens off before winter.

A quick note on sharpening

A clean trowel edge cuts root and weed in one pass. Run a flat mill file along the blade’s bevel a few strokes each spring, then a wipe of linseed oil against rust. That is the whole job.

What the catalogue does not tell you about wilt on damp aspects

Clematis wilt, caused by the fungus Calophoma clematidina, strikes large-flowered hybrids hardest and viticellas least, which is most of the reason the shortlist above leans on the viticella group. On a north aspect the soil stays moist and cool, conditions the fungus tolerates well, so the deep-planting trick matters more here than on a dry south wall. A plant set with its crown 8 centimetres down can lose its entire top to wilt in July and regenerate from the buried buds within the same season.

There is no chemical control available to home growers. The management is cultural: deep planting, good airflow through the espalier framework so foliage dries after rain, and prompt removal of any collapsed stem cut back to healthy tissue or below soil level. Burn or bin the cut material, do not compost it, because the fungus persists in dead stems. The montana and alpina types in Group 1 rarely show wilt at all, which is a quiet argument for weighting a north pergola toward those two groups and treating the summer-flowering viticellas as the replaceable element.

One open question remains for anyone planting now: whether the green-tipped Alba Luxurians, whose colouring deepens in shade, will read as a feature or simply as a dingy white once it is competing for light against the heavier purple of Polish Spirit on the same frame.