Shade Tolerant Annuals And Biennials

Most annuals produce finer results when grown in an open position, but some are adaptable to shade and others actually prefer it. Given moist soil — for few plants thrive in dry shade — they become indispensable for brightening dull corners, growing in north-facing beds or window boxes or establishing beneath the overhanging branches of trees.

Aquilegia

Although strictly perennial the Long Spurred Hybrids derived from Aquilegia caerulea are usually treated as hardy annuals. To this end seed is sown in frames in September or under glass in spring and then planted out. These hybrids come in a wide range of colours and

combinations of shades and all have long protruding spurs behind the flowers. The height varies between 18 and 30 in. They do well in dappled shade and are excellent for borders, also for cutting.

Collinsia

Collinsia heterophylla (bicolor) seed can be sown outside in moist soil and light shade in autumn or spring (according to climatic conditions). This germinates in fourteen days and later the plants need thinning out to about 6 in. apart. The large and showy, purple and white-lobed flowers are carried in clusters on 2-ft. Stems.

Collinsia heterophylla

Cynoglosstun

Cynoglossum amabile or hound’s tongue is a rough-textured biennial from eastern Asia with sprays of turquoise-blue forgetme-not-like flowers on 1 to 2-ft. Stems. The leaves are hairy and oblong. Treat as biennial or sow seed under glass in early spring.

Digitalis

The stately spikes of foxgloves (Digitalis purpurea) are equally beautiful in the formal border — with blue delphiniums, tall campanulas, English irises (I. xiphioides) and the cerise Geranium psiloslemon — as in the wild garden amongst ferns and hostas.

Seed should be sown in drills in May or June and the young plants transferred to their flowering positions when large enough to handle. Incidentally, they will move in full flower — useful to fill up gaps. D. purpurea is purple or white, spotted with brown inside the tubular flowers, but there are also primrose, apricot and various pink forms, with or without spots, also types in which the flowers are borne horizontally, all round the stems. The usual height is 5 to 6 ft. but a dwarf race called Foxy is only 30 in. tall and flowers in five months from sowing.

Hesperis

Hesperis matronalis is the dame’s violet or sweet rocket; a sweetly scented plant something like honesty (Lunaria annua) with white, pale mauve or deep purple, four-petalled flowers on 2 to 3-ft. Spikes. It is a hardy biennial of branching habit; the perfume strongest towards evening.

Impatiens

The brilliant forms of Impatiens holstfi, I. sultanii, I. Petersiana (although correctly now grouped under the collective name of I. wallerana) are generally still catalogued under their old names. In recent years there have been many colour additions — scarlet, rose, crimson, white, orange and bicolours — also dwarf races which have proved excellent for planting outside. These grow between 5 and 8 in. high and should be treated as half-hardy annuals. Damp soil is essential (peat in the soil helps) in either sun or shade.

Meconopsis

The annual and monocarpic species of meconopsis make beautiful additions to shady borders. All require cool, moist conditions. Seed should be sown soon after gathering in a shady frame and the young plants potted but not put outside until early autumn. The beautiful Himalayan blue poppy, Meconopsis betonicifolia (M. bailey°, with large, satiny, sky-blue flowers, can be treated in this way, also M. regia which has flat rosettes of leaves covered with bronze-gold hairs and spikes of bright yellow flowers. The two look delightful grown together in light woodland conditions. Both are 3 ft or so.

Mimulus

Mimulus are really bog plants, so if they are to thrive they must have moist soil, preferably away from hot sun. Most garden sorts, derived from Mimulus luteus and M. cupreus, are treated as half-hardy annuals. Heights vary between 6 and 9 in. and the snapdragon-like flowers come in bright pinks, scarlets, yellows and oranges, often blotched with other shades. Red Emperor Mixed is a particularly good strain.

Nemophila

Nemophila menziesii or baby blue eyes is a delightful Californian annual with deeply cut leaves and masses of large, saucer-shaped blue and white flowers on 6 to 8-in. Stems. It is excellent for massing under a light canopy of tree foliage, but will also grow in rock pockets or shady borders. Sow the seed outside in early spring for summer flowering or in autumn in protected spots for spring blooming.

Viola

Pansies are short-lived perennials derived from Viola tricolor, usually treated as biennials. Their puckish flower faces, in every conceivable colour, are delightful for edging purposes, as a groundwork for other plants or in beds by themselves. Since they like cool moist conditions they do well in light shade, although the winter-flowering races need more open conditions. Sow seed in summer for the following season’s flowering. Violas are very similar except that the plants are tufted and the flowers smaller and frequently self-coloured. Good named sorts have to be propagated from cuttings.

Other annuals which will grow in partial shade are nicotianas, lunaria, Begonia semperflorens and Tropaeolum majus.

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