Nigel Colborn - Plant Solutions

Soil preference:Any free-draining

Aspect:Sun

Season of interest:Summer, autumn

Height and spread:15–50cm (6in–1ft 8in) × 30cm (12in)

Companion plants:A worthy addition to a grass border, especially if planted with other annual grasses such as Briza maxima , but also lovely among flowering annuals. Scatter seed among pot marigolds, cornflowers or tagetes.

Annuals for sheltered sites

Anagallis monellii

Shrubby Pimpernel Perennial grown as a tender annual

A low, straggly plant with semi-trailing stems and small, triangular leaves grouped in threes along the stem. At each leaf joint, buds form which open as conspicuous, five-petalled flowers in the deepest, most intense blue. Similar, but larger in all its parts, to the wild blue pimpernel, Anagallis foemina .

Soil preference:Fertile, well-drained

Aspect:Sun

Season of interest:Summer

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

Companion plants:An excellent hanging basket or container plant which is especially effective when contrasted with bright yellow Bidens ferulifolia or harmonized with variegated trailing Plectranthus or with red pelargoniums.

Cerinthe major ‘Purpurascens’

Honeywort Annual

Cornfield annual from the Mediterranean with curious, glaucous foliage and, in early summer, metallic purple bracts which are remarkably luminous and which half conceal the strange brownish purple and yellow tubular flowers. The seeds are large and stone-hard. Although when established it will self-sow, the species is not hardy in sustained frost.

Soil preference:Any well-drained

Aspect:Sun

Season of interest:Summer

Height and spread:50cm × 30cm (1ft 8in × 12in)

Companion plants:A distinctive plant for a Mediterranean garden among grey and silver-leaved herbs such as lavenders, Teucrium and sages. Excellent in gravel, too, among brown sedges such as Carex buchananii and also with Californian poppies.

Brachyscome hybrids

Swan River Daisy Annuals

The narrow, fresh, often lacy green leaves on these Australian native plants are almost hidden behind a generous covering of bright daisy flowers, in mauve, pink or white. A neat, but semi-trailing habit, coupled with summer-long flowering makes them ideal for container use. Good varieties include ‘Blue Haze’, the lilac coloured ‘City Lights’ and the purple-blue ‘Toucan Tango’. Tender.

Soil preference:Any, reasonably fertile

Aspect:Best in full sun

Season of interest:Summer

Height and spread:45cm × 45cm (18in × 18in)

Companion plants:Yellow-flowered Bidens ferulifolia makes a good contrast, but the silver filigree leaves of Artemisia ‘Lambrook Silver’ or ‘Powis Castle’ also blend pleasingly.

Convolvulus tricolor

Annual

A non-climbing, but somewhat lax plant with small, oval leaves and saucer shaped flowers, similar to those of morning glories, but 5cm (2in) wide. The typical species has dark, royal blue petals, fading white or creamy yellow at the throat. Selected varieties include ‘Ensign Mixed’, with pink, maroon, blue and white shades, and the pale ‘Light Blue Flash’.

Soil preference:Any

Aspect:Sun

Season of interest:Summer

Height and spread:50cm × 30cm (1ft 8in × 1ft)

Companion plants:Great for a mixed annual border or to dot in among such perennials as Mexican salvias, osteospermums or grasses.

Lavatera trimestris

Annual

Tall, bold, with thick, rigid stems and large, slightly hoary leaves, this native of the Mediterranean regions has large, saucer shaped flowers whose stamens and stigma fuse to form a central spike. Colours range from rich pink, in ‘Silver Cup’ and ‘Ruby Regis’, to a startling white in ‘Mont Blanc’. Each petal is veined with darker lines.

Soil preference:Well-drained, fertile

Aspect:Sun

Season of interest:Summer

Height and spread:60–90cm × 45cm (2–3ft × 18in)

Companion plants:Careful siting is necessary, with so conspicuous a plant. Excellent in bold groups on its own or among such large perennials as Galega, leucanthemums and Phlox paniculata , with perennial asters to follow.

Galactites tomentosa

Annual

A thistle with spiky, divided white and green foliage, which emerges in autumn or early spring, forming an attractive rosette. In summer, the stem lengthens and branches, eventually bearing lilac-mauve, tufted thistle flowers. Seed is borne on thistledown. This native of the Canary islands and Mediterranean self-seeds freely, but young seedlings will not survive prolonged frost.

Soil preference:Any free-draining

Aspect:Sun

Season of interest:Spring, summer

Height and spread:1m × 75cm (3ft 4in × 2ft 6in)

Companion plants:Attractive when allowed to colonize areas between shrubs – especially such Mediterranean species as rosemary, lavender, Santolina or Phlomis fruticosa , or to pop up at random in a mixed border.

Annuals for extra poor soil

Briza maxima

Greater Quaking Grass Annual

A free-seeding annual grass which performs best in hot, dry conditions, where the plants are less likely to become invasive. Mid-green, soft grass foliage emerges in autumn or spring. The flower stems are wiry and much branched, bearing cone-shaped flowers which shimmer and tremble in the slightest breeze. Superb for cutting and drying.

Soil preference:Dry, not too fertile

Aspect:Sun or part shade

Season of interest:Summer

Height and spread:60cm × 45cm (2ft × 18in)

Companion plants:A beautiful foil for showy herbaceous plants such as scabious, cornflowers, Linum or Oenothera.

Eschscholzia californica

Californian Poppy Annual or shortlived perennial

A beautiful combination of blue-green, lacy foliage and bright, silky-textured flowers makes this American native a valuable plant, especially for a dry garden. The wild species has bright orange flowers, but seed selections come in a range of sunset hues from cream or primrose yellow, through peachy tones to burnt orange. Best in free-draining soil.