The best clematis for containers and how to grow them in pots

You don't need a border to grow clematis. Plenty of varieties flower happily in a large pot on a patio, balcony or doorstep, provided you choose a compact type and a container that keeps the roots cool and moist.

What makes a good container clematis

Lower-growing types generally do better in containers, says the British Clematis Society, because vigorous clematis use up nutrients and moisture faster. That rules out the giants. Look instead for plants that stay compact, flower over a long season and need little pruning or a simple routine.

Compact clematis worth considering

The heights above are RHS figures for plants in the ground; in a pot, plants are often a little smaller.

'Petit Faucon' (group 3)

Small, upright and non-clinging, with violet-blue flowers up to 9cm across from summer into early autumn. It holds the RHS Award of Garden Merit (AGM), is rated H6 (hardy throughout the UK) and tolerates any aspect. Give it a small obelisk or let it lean on neighbouring plants.

Boulevard series, such as 'Ooh La La' (group 2)

Bred for compact growth, 'Ooh La La' flowers from late spring to late summer and does best in partial shade, so that its flowers don't fade. It suits a shady courtyard or a north-facing doorstep.

'Piilu' (group 2)

Pale pink flowers with a darker central bar, usually double or semi-double in the first flush and single later in summer. The RHS lists it for any aspect.

'Frances Rivis' (group 1)

An AGM alpina-type with nodding, violet-blue spring flowers, hardy throughout the UK and happy in any aspect. Group 1 plants need little pruning, which suits a pot.

Herbaceous clematis

Non-climbing types such as C. heracleifolia are self-supporting, so they need no obelisk or trellis.

For a cold greenhouse: 'Avalanche'

The evergreen C. × cartmanii 'Avalanche' (H4) bears sprays of white spring flowers and can be grown in a container in a cold greenhouse or conservatory. Our guide to evergreen and winter-flowering clematis has more on this group.

Taller hybrids such as the double white 'Arctic Queen' also grow in containers, but need a sturdy support and more watering and feeding than the compact types.

Choosing the pot

Depth matters more than for most patio plants, and thick walls insulate roots against summer heat and winter cold. Clematis like moisture, but not standing water.

Compost and planting

Both organisations favour soil-based compost: the RHS suggests a peat-free, loam-based mix such as John Innes No. 2, the British Clematis Society John Innes No. 3 with added grit. The extra weight helps stop a tall pot blowing over. Plant at the same depths as in the ground (see how to plant a clematis).

Watering

This is where most container clematis fail. A sheltered, south-facing pot may need watering twice a day in hot weather, and letting the compost swing between soaking and bone-dry stresses the plant and invites powdery mildew. Water until it runs from the base, and don't leave the pot standing in water.

Feeding

Plants in pots depend entirely on you for nutrients. The RHS recommends an organic, general-purpose liquid feed at the dose on the pack; the British Clematis Society suggests a half-strength high-potash feed every fortnight for large-flowered types, which it calls heavy feeders. See our guide to feeding and watering clematis.

Pests and winter care

Shade the roots with trailing plants in the same pot, or stand another pot on the sunny side. Hardy H6 types can stay outside in winter, but keep drainage clear, because a frozen, waterlogged pot is a real risk.

A plant that flowers poorly despite feeding may simply have outgrown its pot. Move it into the ground or a larger container in spring.