Combining clematis with roses: choosing, planting and pruning

Clematis and roses are one of the great partnerships of the British garden. A climbing rose gives a clematis a ready-made frame to scramble through; the clematis adds colour before, alongside or after the roses, and can hide the bare lower stems that many climbers develop. Getting the partnership right is mostly a matter of choosing the right clematis and planting it so that both plants can thrive.

Why late-flowering clematis are the usual choice

Most experienced gardeners pair roses with group 3 clematis: the viticellas, texensis hybrids and late large-flowered types that flower from midsummer onwards on the current year's growth. There are three good reasons.

• Pruning lines up. Group 3 clematis are cut hard in late winter, to 15–30cm according to the RHS. That is also when roses are pruned, so you can clear the clematis out of the way, prune the rose properly and let the clematis grow back through it.
• The rose isn't smothered. Because group 3 clematis start again from low down each year, they don't build up a heavy mass of old stems over the rose.
• Disease tolerance. The RHS describes C. viticella as tolerant of clematis wilt, a useful quality in a mixed planting where the base of the clematis is hard to reach.

For more on how the groups work, see our guide to clematis pruning groups.

Good clematis for roses

All of these are group 3 clematis named in RHS pruning advice.

• 'Étoile Violette': velvety, deep purple viticella flowers from mid to late summer; AGM, 2.5–4m.
• 'Polish Spirit': a vigorous late clematis with rich purple flowers; AGM.
• 'Princess Diana': a texensis hybrid with upward-facing, tulip-shaped pink flowers; AGM.
• 'Perle d'Azur': clear pale blue flowers from midsummer to early autumn; AGM. It can also be pruned as group 2.
• 'Alionushka': nodding pink bells on a non-clinging plant that, as the British Clematis Society notes, needs tying in or can be left to flop. It is ideal for leaning into a shrub rose.
• Other viticellas: the British Clematis Society lists many more, including 'Alba Luxurians', 'Madame Julia Correvon', 'Kermesina' and the scented 'Betty Corning'.

What to avoid

Steer clear of vigorous early flowerers, particularly C. montana. The RHS lists some montana cultivars at 8–12m, and because they flower on the previous year's wood they can't be cut back in winter without losing flowers. Over a rose, they build up into a heavy mat that blocks light and is almost impossible to untangle. Large-flowered group 2 hybrids can work on a robust climber, but their lighter pruning leaves more old growth in the rose, and many are more prone to wilt.

Matching the plants

Size and vigour

Match the clematis to the rose. A modest shrub rose suits a compact or non-clinging clematis such as 'Alionushka' that drapes rather than climbs, while a big rambler or established climber can take a 3–4m viticella. Planting the clematis once the rose is established helps, so the young rose isn't overwhelmed.

A healthy host

Choose a rose that is already healthy and vigorous, with a sturdy framework of stems. A rose that struggles with disease or poor growth will struggle more with a clematis on top of it. On a wall or fence, make sure the support is strong enough for both: wires or trellis for the rose will usually serve the clematis too, as long as there are thin stems or wires for its leaf stalks to grip.

Timing

The British Clematis Society suggests deciding whether you want the clematis to flower before, with or after its host, and checking that it will climb without damaging it. A rose that flowers once in early summer, followed by a viticella from July, stretches the season; a repeat-flowering climber with a clematis flowering at the same time gives a bolder combined display.

Colour

There is no single rule, but purples and blues tend to sit well with most rose colours. Deep purple 'Étoile Violette' against a pale pink or white rose, or pale blue 'Perle d'Azur' with a soft yellow or apricot rose, are examples. Before you commit, hold a cut flower of one against the other.

Planting the clematis

Roses and clematis are both hungry, thirsty plants, and an established rose has a head start. Avoid planting the clematis right against the base of the rose, where the roots compete most. The RHS advice for planting clematis into trees and shrubs is to plant at least 1.2m from the base, on the windward side, so rain reaches the roots. A rose needs less room than a tree, but the principle is the same: keep the clematis out of the densest part of the rose's root zone.

• Dig a generous hole and improve the soil with well-rotted organic matter.
• Plant at the correct depth for the type; most group 3 viticellas go in with the top of the rootball just below soil level (see how to plant a clematis).
• Lead the stems into the rose along a cane angled towards it.
• Shade the base with low planting or a few stones.

Pruning both together

The routine is straightforward. In February or March, cut the clematis stems back to a low pair of buds, untangling the dead top growth from the rose as you go. Then prune the rose in the usual way. As new clematis shoots appear in spring, guide them into the rose and tie them in loosely. The British Clematis Society suggests pruning viticellas to about 50cm from the ground in late February or early March, a little higher than the RHS figure. Either works, and a slightly higher cut gets the clematis into the rose sooner.

Feeding and watering the pair

Two plants sharing one patch of soil need more support than one. Mulch both each spring with organic matter, water deeply in dry spells and choose a feed with plenty of potash, which encourages flowers rather than leafy growth. Our guide to feeding and watering clematis covers this in more detail.