10 award-winning perennials for containers

For gardeners who want containers that look good for longer, perennials are a confident choice. Offering structure, seasonal interest and dependable performance, they transform pots into features that evolve through the year rather than fading after a single season.

Each of the plants featured here has been put through its paces in RHS Plant Trials, where they are grown side by side and assessed for qualities such as vigour, floriferousness and garden worthiness. Only those that consistently impress an expert judging panel, and are ratified by the relevant RHS Expert Group, receive the RHS Recommended: Award of Garden Merit, making them some of the most reliable choices for container growing.

Perfect for shady gardens

This is an evergreen perennial with large, glossy dark bronze-purple leaves

A shade lover for the front of a mixed container, Ajuga reptans ‘Catlin’s Giant’ combines impact with the tendency to trail over the edge and soften the lines of large pots. In spring, spikes of deep blue flowers, emerge from amongst large darkly bronzed leaves, the foliage becoming greener with age but the new leaves bronzed. Usually needs young pieces replanted after three years. Vigorous, may trail to the ground then root. Height 20cm (8in) Hardiness rating H7.

Heart-shaped leaves

Sprays of small blue flowers appear among these leaves in spring

As a specimen in a 25cm (10in) pot, or as part of a mixed planting in a larger container, the brightly silvered foliage of Brunnera macrophylla ‘Jack Frost’ brings light to the shade in which it is happy to grow. The bold, roughly textured, heart-shaped leaves make an ideal background for the clouds of small, blue forget-me-not spring flowers. Takes some drought, but will burn if drought is combined with too much sun. Height 38cm (15in). Hardiness rating H6.

Pink and fragrant

Richly fragrant, semi-double flowers

The intricate patterning of the prettily fringed flower of Dianthus ‘Gran’s Favourite’, with its blood red heart, repays close inspection so is ideal for a sunny container on the corner of the patio or by the door – where its rich fragrance, and its grey foliage, will also be appreciated. Introduced in the mid 1960s, its stems can be weak so a little very discreet support – or the support of container neighbours – will be valuable. Height 35cm (14in). Hardiness rating H6.

Rich mauve flowers

Shortlisted for the Chelsea Plant of the Centenary for the decade 1973-1982

This classic perennial

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

wallflower appreciates sun, and some close neighbours to fill in the space at the base where its leaves tend to drop off. That greyish evergreen foliage crowds the strong stems which are topped by spikes of pale mauve flowers which darken as they age. May become top heavy eventually, and will usually need replacing after three years. Erysimum ‘Bowles’s Mauve’ flowers almost all the year round and very rarely sets seed. Height 75cm (2 12 ft). Hardiness rating H4.

Long-lasting bloom

A long season bloom from early summer to autumn

Geranium Blue Sunrise is the best of all perennials for a container, especially in a smaller garden. It also makes splendid specimen in a large clay pot. In March, new shoots emerge with yellow leaves brightly edged in red. Chionodoxamake ideal companions. Then, as the shoots develop and the foliage matures, its bright yellow colouring is like a shaft of sunshine. Finally, all through summer, there’s a long season of blue flowers. Lovely. Height 40cm (112 ft). Hardiness rating H7.

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Golden grass

To keep in best shape, cut back old, flowered stems and dead foliage at the bases in late winter

When Adrian Bloom first showed large pots of mature variegated

Variegated means having leaves or other plant parts with streaks, blotches or patches of different colours. Typically, these would be a combination of two colours, such as green and gold or green and white.

hakonechloas at Chelsea twenty years ago or more, it was a new idea. Now, the delicate fountains of white- and yellow-striped, green foliage of Hakenechloa macra ‘Alboaurea’ are recognised as one of the most lovely features for containers. Developing slowly but surely, ideal in partial shade, maturity is worth the wait. Regular watering and feeding is helpful. Or cheat and plant three in one pot. Height 35cm (1ft). Hardiness rating H7.

Deep tones

Grows well in a fertile and moist but well-drained soil in the sun or partial shade

Many heucheras are good in containers, but those with a little subtlety and some intriguing colouring are ideal in pots along paths or by doorways where they can be seen up close. The young foliage of Heuchera ‘Purple Petticoats’ is bronzey red, the mature foliage is bronze-tinted green, but the edges of each leaf are so dramatically ruffled (increasingly so in cold weather) that the bright red-purple undersides spark through. Cream flowers. Height 60cm (2ft). Hardiness rating H6.

Chartreuse leaves

Bright pale yellow leaves emerge and then darken to chartreuse

Most hostas are good in containers, from big bold specimens to miniatures, but Hosta ‘Fire Island’ is another perennial where looking closely is well repaid. The yellow-green leaves with their distinct, symmetrically arranged veins, are supported on bright red stems. But the colouring in the stems is extended into the leaf itself in the form of a line of bright red speckles. Lovely with a bright yellow carpet of Lysimachia nummularia ‘Aurea’. Height 35cm (1ft). Hardiness rating H7.

A dense perennial

This plant is ideal in many locations, including as a patio or container plant, or in wildlife gardens

Euphorbia x martini ‘Helen Robinson’is a dense, upright, spreading, evergreen perennial. The neat, green leaf rosettes

Rosettes are the circular arrangement of flower petals; or a cluster of leaves radiating from approximately the same point usually around a stem. Examples include aeonium and most succulent plants, African violets, primula, sempervivums.

are covered in thick, soft hairs when young and the flowers, produced from mid-spring, are yellow-green with a red eye. Height up to 80cm (31in) tall. Hardiness rating H5.

Bold and ‘Evergold’

Easy to grow in most moist but well-drained fertile soils

Carex oshimensis ‘Evergold’ is an evergreen sedge, with its narrow arching leaves each having a central yellow stripe. Flower spikes appear in the summer and are brown and inconspicuous. Height up to 30cm (11in). Hardiness rating H7.