Good Annuals And Biennials

Althaea

Because of rust disease the perennial hollyhocks (Althaea rosea) and the fig-leaved A. ficifolia are usually treated as hardy biennials. Their tall (6 to 9 ft.), stately spikes of single or double rosette flowers are ideal for backs of borders or as accent plants in key positions. They should be planted in full sun in heavy but rich and well-drained soil; staking the spikes if necessary. Colours range from pink, rose and maroon to white, apricot and yellow.

Arctotis

Arctotis or African daisies are vigorous plants with hairy, silvery-grey stems and foliage and 3 to 4-in, flowers of cream, yellow, orange, red, crimson or purple — frequently zoned with other shades — on li-ft. Stems. To encourage a bushy habit pinch out the tops when the seedlings are 5 to 6 in. tall. Because of their mixed background African daisies are usually catalogued as Arctotis hybrida. Treat them as half-hardy annuals and grow them in an open sunny position.

Arctotis

Argemone

Argemone mexicana is the prickly poppy and it likes a hot sunny situation. It grows about 2 ft. with glaucous, prickly foliage and bright yellow, poppy-like flowers about 3 in. across.

Atriplex

Atriplex hortensis cupreata is a wine-redfoliaged spinach, a useful foliage plant for borders and cutting. It grows up to 4 ft. and should be treated as a hardy annual.

Calceolaria

Calceolaria chelidonioides is a South American annual with long succulent leaves and honey-scented, lemon-yellow, pouched flowers on 12 to 18-in. Stems. The shrubby C. integrifolia (C. rugosa) can also be grown from seed; Golden Bunch being a particularly fine flowering, 8-in. Variety. Treat as half-hardy annuals and place in a warm, sunny situation.

Campanula

Canterbury bells (Campanula medium) are delightful biennials for mixed borders, especially in rich soil with plenty of sun. In windy situations they may need staking. The bell-shaped flowers come with or without ‘saucers’ in white, pink, blue and mauve and there are dwarf races such as the 18-in. Musical Bells. C. pyramidalis, the chimney bellflower, is also grown as a biennial, but with protection in winter. The beautiful blue or white flowers are saucer shaped on 4-ft. (to 8 ft. under glass) spires.

Centaurea

Centaurea cineraria (C. candidissima) is grown for its fine silvery leaves which set off bright annuals and have many garden uses. It likes sun and well-drained soil, growing about 15 in. high. C. gymnocarpa is similar but with wider leaves and taller at 2 ft. Both plants are perennials but can be killed in cold winters so treat as half-hardy annuals.

Cladanthus

Cladanthus arabicus has deeply cut leaves and bright yellow daisy flowers on 12 to 15-in. Stems. It appreciates sun and should be grown as a hardy annual.

Convolvulus

Convolvulus tricolor is a delightful hardy annual for full sun, growing 12 to 15 in. tall with brilliant blue, funnel-shaped flowers with white or pale yellow throats. There are also kinds with white, rose and dark blue flowers.

Echium

Echium lycopsis (E. plantagineum) or viper’s bugloss is a hardy annual with spikes of bright blue flowers and rough leaves and stems. It grows 9 to 12 in. tall and there are white, pink, purple and mauve-flowered forms.

Gazania

Gazanias are best treated as half-hardy annuals although named or selected varieties can be perpetuated from cuttings. They must be grown in full sun since the flowers fail to open in dull weather or shade. The long, narrow, ground-hugging leaves have a silver reverse and the brilliant daisy flowers come in cream, orange and pink, often with striking zonings such as green on pink and orange on silver.

Helianthus

Helianthus annuus is the common sunflower, a hardy annual with huge platelike golden flower heads up to 1 ft. in diameter on 4 to 10-ft. Stems. Seedsmen also sell dwarf sunflowers on 3 to 4-ft. Stems, with orange, yellow, cream and chestnut-brown flowers.

Lavatera

Lavatera trimestris rosea, one of the best of the taller hardy annuals, has large open, satiny-pink flowers like mallows on its branching stems. These are in character all summer and require full sun and good soil. Height 24 to 30 in. One of the best strains is called Loveliness and there is also a white form.

Linum

Linum grandiflorum rubrum is a red-flowered flax, very showy, with slender 12-in, stems carrying many saucer-shaped, deep red blooms. It likes sun and only shows to advantage in bright weather. Hardy annual.

Mentzelia

Mentzelia lindleyi (Bartonia aurea), an easy hardy annual, has large, golden, chalice-shaped flowers full of stamens on 18-in. Stems. It is also known as blazing star, likes sun and is sweetly scented.

Oenothera

Oenotheras may be annual, biennial or short-term perennials; many are night bloomers. The common evening primrose (Oenothera biennis) sows itself about after initial establishment, the 2 to 4-ft. Stems carrying many 2-in., lemon-yellow, sweetly scented flowers. Another night-scented biennial is the shorter (12 in.) O. trichocalyx with white flowers. O. acaulis, although perennial, should be treated as a half-hardy annual and is worth the trouble as the 4-in, flowers on trailing stems are very beautiful. They open white and develop to deep rose.

Silene

Silenes are showy plants for the border or rock garden with small white, pink or purple-pink flowers. The annual Silene pendula, growing 6 to 8 in., makes compact plants covered with bloom in spring from autumn sowings. In cold soils, however, they may need winter protection. There are double forms as well as singles. S. armeria grows taller — 1 to 2 ft. — and has sticky stems.

Tithonia

The Mexican sunflower (Tithonia rotundifolia) is a rapid grower, up to 9 ft. and 6 to 10 ft. across. Its broad branching habit supports many large, single, orange, zinnia-like flowers from July onwards. Treat as a half-hardy annual and plant in sun.

Verbascum

Verbascums (mulleins) carry their flowers on long straight spikes. They like sun and well-drained soil. Although perennial, some can be grown as hardy annuals. Verbascum olympicum is yellow and 5 to 6 ft.; V. phoeniceum, red, purple, pink, white or mauve and 2 to 3 ft. tall.

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