Aspect: Sun or part shade
Season of interest: Summer
Height and spread: 50cm × 30cm (20in × 12in)
Companion plants: Blue forms contrast sharply with the yellows of verbascums or, from later sowings, goldenrods and yellow daisies such as rudbeckias and heleniums. The intense blue would also relieve the monotony of a cool, silvery or white theme.
Datura inoxia
Downy Thorn Apple Annual
A large, much branched, characterful annual with big, oval leaves which are downy and slightly tacky to the touch. The huge trumpet flowers – 15cm (6in) or more long – are purple tinged when in bud, but open to a soft white. In the evening and at night they are heavily scented.
Soil preference: Any fertile soil
Aspect: Sun
Season of interest: Summer, autumn
Height and spread: Up to 1m × 1m (3ft 3in × 3ft 3in)
Companion plants: One to grow on its own, but for a heady cocktail of night fragrance, plant with fragrant tobacco Nicotiana affinis and the vanilla scented heliotrope.
Malope trifida
Annual Mallow Annual
Similar to annual Lavetera trimestris, but slightly smaller with more downy, heart-shaped leaves that hang down as the plant matures. Big saucer shaped flowers appear in succession throughout summer and colours in the various seed selections range from dusky and rose pink to bright magenta, deep plum and white.
Soil preference: Fertile but well-drained
Aspect: Sun
Season of interest: Summer
Height and spread: 50–75cm × 45cm (1ft 8in–2ft 6in by 1ft 6in)
Companion plants: Better than lavatera for mixing with other such hardy annuals as cornflowers, clarkia, larkspurs, Convolvulus tricolor and corn cockle.
Zinnia elegans
Annual
The species has been used to develop a colourful range of tender annuals, with simple leaves, slightly rough to the touch, and flowers with attractive layered florets, often with dark ochre or yellowish fertile centres. Flower colours include white, yellow, pink, mauve, orange, red, maroon and even pale green with a variety of flower forms from single to pompon.
Soil preference: Fertile, free-draining but not too dry
Aspect: Sun, shelter
Season of interest: Summer
Height and spread: From 20cm × 30cm to 1m × 50cm (from 8in × 3ft to 3ft 3in × 1ft 8in)
Companion plants: As desirable for cutting as for garden use, Zinnias will benefit from softer, more diffuse shapes nearby. Goldenrods add extra summer yellow, with a contrasting texture. Pale mauve or blue varieties of perennial aster will tone down the zinnias’ jazz.
Borago officinalis
Borage Annual
Large, heart-shaped to oval puckered, hairy leaves and thick, fleshy, branched stems carry myriads of small, star shaped flowers which are intense sky blue, with pale centres and dark, spiky stamens. A rapid annual which self-seeds copiously.
Soil preference: Any
Aspect: Any
Season of interest: Summer, autumn
Height and spread: Up to 1m × 75cm (3ft 3in × 2ft 6in), usually smaller
Companion plants: Beautiful anywhere but easily pulled out if not welcome. Herbs such as lavenders, herbaceous perennials, shrubs, large grasses, roses and bedding plants all make great companions.
Phacelia tanacetifolia
Fiddleneck Annual
Handsome American species, often used as a ‘green manure’ crop. The compound leaves, reminiscent of Jacob’s Ladders, create a ferny effect as the branched stems develop and lengthen. Buds are carried on tightly curled scapes, like violin heads, which uncurl and straighten as the violet blue flowers open. A free seeder.
Soil preference: Any, not too wet
Aspect: Sun or part shade
Season of interest: Summer
Height and spread: Up to 1m × 60cm (up to 3ft 3in × 2ft)
Companion plants: Another charming annual to sow in drifts among grasses or naturalistically planted perennials. The soft lavender-blue haze they create is also pretty with creamy or sunset-hued achilleas or among blue cranesbills.
Annuals for containers
Antirrhinum pulverulentum
Trailing Snapdragon Half hardy perennial, grown as an Annual
A compact, but trailing plant with oval, dull-green leaves and a long succession of ‘snapdragon’ flowers whose lips gape when gently pinched. Hybrids include the series ‘Pendula Lampion’ with pale pink, white or purplish flowers and pale yellow markings. Antirrhinum hispanicum subsp. hispanicum has silvery grey leaves and purplish pink blooms.
Soil preference: Any free-draining
Aspect: Sun
Season of interest: Summer and autumn
Height and spread: 15cm trailing 30cm (6in trailing 1ft)
Companion plants: Equally effective in hanging baskets, window boxes or alpine troughs. Their pastel hues blend gently with the grey-green foliage of Helichrysum petiolare or with white-variegated Glechoma hederacea ‘Variegata’.
Celosia argentea
Cockscomb or Wool Flower Tender annual or shortlived perennial
Vigorous, soft-textured plants with pointed leaves and successions of bold, highly coloured plume-like flowers in vivid shades including red, orange, yellow and purple. ‘Fresh Look Red’ has scarlet flowers. The mixed ‘Look Eternal Flames’ has either bright yellow or burning red flowers, accompanied by foliage which is green or deep purple-bronze.
Soil preference: Free-draining but moist and fertile
Aspect: Sun
Season of interest: Summer
Height