10 award-winning summer perennials

Popular, diverse and versatile,

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.

Easy to grow purple

Best in full sun but can tolerate light partial shade

Perennial salvias come in a vast variety of styles, but the short and prolific summer flowering types, such as Salvia nemorosa ‘Amethyst’, are easy and invaluable. The stems branch well from the base and the long spikes of flowers open from June, keep coming till October and retain their purple colouring even after the individual florets have dropped. Prolific in any sunny place with well-drained fertile soil. Grows to 60cm (2ft). Hardiness rating: H6. 

Crimson eye-catcher

Grow in fertile, moist soil in full sun or partial shade

Phlox paniculata ‘Starfire’ is an upright

Deciduous refers to plants (mainly trees and shrubs) that lose their leaves seasonally, usually during autumn. This is a natural process triggered by the season's shorter days and lower temperatures and allows plants to conserve energy during the winter months.

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.

perennial

Vivid pop of colour

Grow in deep, fertile, well-drained soil in full sun or partial shade

Oriental poppies come in both brash, vivid colours and delicate pastel shades and the soft pink of Papaver orientale ‘Karine’, enlivened by a rather variable reddish basal zone, is a lovely May/June partner for tall bearded irises. Best with discreet support to prevent rain knocking them over, the foliage turns ragged after flowering but Cosmos planted nearby will expand to hide it. Happy in sun and most good soils. Grows to 60-70cm (24-28in). Hardiness rating: H7. 

Double white flowers

Grow in moderately fertile, moist but well-drained soil

Leucanthemum × superbum ‘Wirral Supreme’ is a robust herbaceous perennial with narrow, dark glossy green leaves and double white flowers 10cm in width, with short, pale yellow central florets. Grows to 90cm (35in) in height. Hardiness rating: H5. 

Prolific flowerheads

Grow in full sun and fertile, moist but well-drained soil

With impressive vertical spikes of golden orange flowers from May to July, Kniphofia ‘Bees’ Sunset’ becomes brighter and then yellow as they age, and are held on harmoniously coppery green stems. The flower heads look a little disorganised but are bright and prolific. Happiest in deep, rich soil in full sun and with good winter drainage. Named for Bees Nursery, who financed the plant hunting trips of George Forrest and Frank Kingdon-Ward. Grows to 75-120cm (30-48in). Hardiness rating: H5. 

Violet with blue sparkles

Grow in well-drained, fertile, neutral to slightly acid loam in full sun

No perennial or mixed border is complete without tall bearded iris and ‘Titan’s Glory’ features unusually large violet flowers with ruffled edges, plus the sparkle of a bright blue beard. The fragrant flowers have real presence, are at their best in June and enjoy full sun and any well-drained fertile soil. Every three years, divide and replant after flowering. Grows to 95cm (38in). Hardiness rating: H7. 

Purple veins 

Grow in moderately fertile well-drained soil in full sun or partial shade

Geranium ‘Orion’ is a spreading perennial, ideal for groundcover, with deeply lobed mid-green basal leaves in seven divisions. Masses of very large, cup-shaped, lavender-blue flowers have purple veins, a white centre and almost round, overlapping petals borne over a long period during summer. Grows to half a metre in height. Hardiness rating: H7. 

Blood-red centre

Grow in a well-drained, neutral to alkaline soil in full sun

New garden pinks, with their fragrant flowers set off by slender grey foliage, are introduced every year but the 40-year-old Dianthus ‘Cranmere Pool’ is still well worth growing. The large

A type of flower that has extra petals, often having a fuller appearance. Plants with double flowers are often considered more ornamental and showy than those with single flowers, though they are generally not as good for wildlife, having little or no pollen. Some plants naturally produce double flowers, while others may be bred for this trait. Examples of plants with double flowers include roses, sunflowers, dahlias, and zinnias.

A classic blue

Grow in a fertile, well-drained soil in full sun. Shelter from strong wind

A classic blue delphinium, the spikes are packed with vibrant gentian blue flowers, each with a dark eye. The florets are small compared with some similar varieties, but Delphinium ‘Fenella’ has the advantage of being a robust and resilient garden plant and makes a vivid impact at the back of the border. Best in sun, in fertile soil that is not too wet; staking is essential. Grows up to 1.5-1.8m (5-6ft). Hardiness rating: H5. 

Stark white petals

Will grow in any garden soil but avoid moving around

Anemone × hybrida ‘Honorine Jobert’ has pure white flowers, with broad overlapping petals around a ring of golden anthers and a green eye, open on branched airy stems from August to October above bold dark leaves each with three leaflets. Happy in sun or a little shade, and best staked discretely – just in case – but can be over vigorous. Introduced as long ago as 1858, and sometimes sold simply as ‘Alba’. Grows to 50-120cm (20-48in). Hardiness rating: H7.