Nigel Colborn - Plant Solutions

Aspect:Sun

Season of interest:Summer

Height and spread:60cm × 30cm (2ft × 1ft)

Companion plants:Valuable as a green manure, to be dug in before seeds are set, but also highly decorative among annuals or dotted among sun-loving Mediterranean shrubs such as Cistus, Artemisia and Helichrysum.

Dianthus chinensis

Hardy biennial

Fast-maturing species which has given rise to many garden series. The simple, narrow green leaves are all but hidden by the crop of brightly coloured flowers with pinked or serrated petals. Fine forms include the maroon and white ‘Black and White Minstrels’, brilliant red or white ‘Magic Charms’ and the pink or red ‘Victoriana’ series.

Soil preference:Any free-draining

Aspect:Sun

Season of interest:Summer

Height and spread:30cm (1ft), variable by 20cm (8in)

Companion plants:Superb container plants, to blend with other summer flowers such as Lobelia erinus or with the foliage of Plectranthus and Glechoma hederacea ‘Variegata.’

Angelica gigas

Giant Angelica Hardy biennial or short-lived perennial

A big, clump-forming plant which may take two or three years to flower. The three-part leaves are large and green but carried on purplish stems. The flower buds form in dark, bulging sheaths and open to form attractive, purplish umbels. An East Asian plant of great character which, if happy, will self-seed.

Soil preference:Fertile, not too dry

Aspect:Sun or part shade

Season of interest:Spring, summer, autumn

Height and spread:2m × 1m (6ft × 3ft)

Companion plants:A big monster to grow with lilies, perhaps, in semi-shade among shrubs, or to bring later interest in a woodland garden, perhaps among Fothergilla, magnolias, Enkianthus or to grow under wide-spaced trees in a large scale planting.

Brassica oleracea

Kale ‘Redbor’ Hardy biennial

Purple curly kale. A decorative and edible member of the cabbage family with thick, erect stems and deeply creased and ruched leaves. The stem colour is bright rose purple, darkening to deep red-purple in the puckered leaves. In its second spring, pale yellow flowers are produced. Excellent for flavour, as well as ornament.

Soil preference:Any fertile, free-draining

Aspect:Sun

Season of interest:Summer, winter

Height and spread:75cm × 45cm (2ft 6in × 1ft 6in)

Companion plants:Superb with the strong colours of late summer perennials such as chrysanthemums, rudbeckias, Mexican salvia spieces and with Swiss or Rhubarb chard.

Beta vulgaris

Chard Hardy biennial

Usually grown as a vegetable, but a highly decorative plant. Huge, puckered leaves with thick midribs which may be coloured. When the plants bolt, coarse seedheads form and the ornamental and culinary value diminishes. Pretty varieties include ‘Bright Lights’ (red, white and yellow stems), ‘Lucullus’ (white stems) and ‘Charlotte’ (bright red stems with dark leaves).

Soil preference:Any

Aspect:Sun

Season of interest:Spring, summer

Height and spread:To 75cm × 30cm (2ft 6in × 1ft)

Companion plants:Lovely for an ornamental kitchen garden, or simply to mix in with a summer flower border to add substance and colour.

Pastel-coloured Brompton stocks ( Matthiola incana ) not only create attractive displays in any garden, but also attract bees with their powerful scent.

Planting Biennials for Spectacular Schemes

Biennials can be useful among more permanent flowering plants such as shrubs or perennials. Their temporary nature can be advantageous, enabling them to provide a spectacular show in their season, and then disappearing to leave an uncluttered space for the permanent plants to take over. Alternatively, they can be timed to complement their companion shrubs or perennials.

Spring-flowering biennials such as wall flowers or forget-me-nots are useful, not only for early colour, but also to relieve the monotony of deciduous shrubs or emerging perennials whose period of beauty is yet to come. They can be deployed as fillers, giving background colour to more brilliant performers such as tulips, or can be used to provide drifts of colour in their own right.

Although the same colour, the shape of Digitalis purpurea (foxglove) contrasts with that of the rose, ‘Climbing Iceberg’.

Stark contrast

The rose ‘Climbing Iceberg’ is teamed (below, left) by a white seedling foxglove, Digitalis purpurea . The colours harmonize, but the shapes and character of the plants are in stark contrast with each other. When the flowers of the foxglove are over, the whole plant can be pulled out or can be allowed to set seed for next year’s repeat show.

Informal air

A very loose, informal planting of climbing roses along an old limestone wall is enhanced by a drift of sweet Williams – Dianthus barbatus (below, right). The contrasting rose colours – ‘Scharlachglut’ (‘Scarlet Fire’) and ‘Gloire de Dijon’ – make a cheerful splash above the biennials, which help to draw the eye downwards and along the border. This is an early summer display but later, when the Dianthus are over, the scarlet rose will carry a conspicuous crop of orange hips, accompanied in the border by lilac-coloured colchicums.

Dual-purpose biennials

Some biennials are valuable as dual-purpose plants, creating attractive displays in beds or borders, or as cut flowers. In the main picture, opposite, these Brompton stocks have rich pastel colours and an intense fragrance, making them ideal for both purposes.

Sweet Williams, loosely planted in drifts, go well with roses up against a garden wall.

Bedding: spring flowering, full and dappled shade

Bedding: summer flowering, full sun

Bedding: summer flowering, dappled shade

Bedding for attracting wildlife

Bedding: spring flowering, full and dappled shade

Bellis perennis

Double Daisy, Lawn Daisy Perennial

Rounded or spoon-shaped leaves create mats of foliage above which blooms are held on thin stems. The wild species has a golden flower centre, surrounded by white sterile florets whose edges are flushed pink. Garden varieties include the double ‘Pomponette’ series, pale pink ‘Dresden China’ and the reddish ‘Rob Roy’.

Soil preference:Any

Aspect:Sun or partial shade

Season of interest:Spring

Height and spread:Up to 15cm × 20cm (6in × 8in)

Companion plants:Beautiful when bedded with forget-me-nots and with such bulbs as hyacinths or tulips.

Hyacinthus orientalis

Hyacinth Bulb

Fleshy, dark green leaves emerge in early spring. Later, chunky flower buds appear and extend to form thick flower spikes in shades of pink, blue, purple, white, pale yellow and orange. Intensely fragrant. ‘L’innocence’ is a fine bedding white, ‘Delft Blue’ is mid-blue, ‘Queen of the Blues’ darker and ‘Anna Marie’ pale pink.