Plant Solutions

Height and spread: To 25cm × 25cm (10in × 10in)

Companion plants: Usually bedded when grown as biennials and excellent with tulips or with wall flowers. Yellow or red series look fine with blue forget-me-nots.

Verbascum bombyciferum

Giant Mullein Hardy biennial

Huge rosettes of downy, pale grey leaves develop in the first year, followed in the second summer by towering, white felted flower spikes which are furnished for months with chrome yellow flowers. Food plant of the Mullein moth caterpillar; flowers attractive to bees.

Soil preference: Any free-draining

Aspect: Sun

Season of interest: Year round

Height and spread: 2.5m × 1.5m (7ft 6in × 4ft 6in)

Companion plants: One for bringing drama to a dry border. Try with airy grasses, or with other large, drought tolerant perennials such as Crambe cordifolia or Colquhounia coccinea.

Echium pininana

Tower of Jewels, Pride of Tenerife, Tree Echium Tender biennial

A bizarre giant bugloss from the Canary islands. Bristling, thick stems with narrow leaves extend during summer and carry thousands of small, violet blue or pinkish-tinged flowers. May take more than a year to reach flowering size, but always dies after flowering. Loved by bees.

Soil preference: Any free-draining

Aspect: Sun

Season of interest: Summer

Height and spread: 3m × 1m (10ft 9in × 3ft 3in)

Companion plants: Grown as a curio, but handsome when the flower stem begins to rear up amongst plants in a Mediterranean style border.

Salvia argentea

Hardy biennial or short-lived perennial

Large, oval, densely felted foliage forms large, flat rosettes from early summer. The small, greenish white, lipped flowers are held on branched stems which are square in section. A free self-seeder but young plants are susceptible to water logging, especially in winter. Loved by bees, butterflies and adult hoverflies.

Soil preference: Any free-draining

Aspect: Sun

Season of interest: Summer

Height and spread: 45cm × 45cm (1ft 6in × 1ft 6in)

Companion plants: The broad leaves contrast sharply with the small, spiky stems and foliage of rosemary, lavender and Russian sage (Perovskia)

Rudbeckia hirta

Half hardy biennial or short-lived perennial

Oval, pointed leaves and somewhat hairy, branched stems bear, during late summer and autumn, big daisy flowers whose prominent central cones are usually dark and whose outer ray florets are broad, long and richly coloured in yellow, orange, mahogany or combinations of these hues.

Soil preference: Fertile, well-drained but moisture retentive

Aspect: Sun or part shade

Season of interest: Late summer and autumn

Height and spread: Variable to 1m × 45cm (3ft 3in × 1ft 6in)

Companion plants: Bright companions for red salvias or among cooler blues and mauves of autumn-flowering asters. Also useful for late bedding schemes.

Biennials for scent

Dianthus barbatus

Sweet William Hardy annual or short-lived perennial

Member of the pink family, its branching stems furnished with broad or narrow dark green or purple-bronze leaves, are topped with clusters of flowers. The sepals are narrow and extended like little green beards. The fragrant blooms are maroon, red, pink, white or bicoloured and last for several weeks.

Soil preference: Any free-draining

Aspect: Sun

Season of interest: Early to midsummer

Height and spread: To 60cm × 45cm (2ft × 1ft 6in)

Companion plants: Great favourite for cottage planting and good company for annuals such as larkspurs and cornflowers, or to grow at the feet of climbing or bush roses. Also prized as a cut flower.

Viola x williamsii ‘Bedding Supreme’

Miniature pansy Hardy biennials or short-lived perennials

Seed-raised selections of small-flowered pansies or violas with honey-scented, five-petalled flowers produced above lobed leaves. short-lived as perennials, but can be kept in flower for months by regular deadheading. Good series: ‘Bedding Supreme’ comes in a broad colour mix, ‘Singing in the Blues’ in shades of purple, violet and blue.

Soil preference: Any free-draining but not too dry

Aspect: Sun, part shade

Season of interest: Winter, spring, summer

Height and spread: 20cm × 30cm (8in × 12in)