Height 15-45cm (6-18in)
Planting distance 25-38cm (10-15in)
Flowersto early summer
Well-drained fertile, preferably alkaline or neutral
With its dense spikes of richly coloured blooms and its heady fragrance, the wallflower deserves its reputation as the queen of spring and early-summer flowering biennials. Many cultivars are now available, providing the gardener with an enormous range of colours to choose from: shades of yellow, apricot, pink, purple, and strong clear reds, oranges and yellows. All have spikes of freely producedand green lance-shaped leaves.
Most varieties are anything up to 60cm (2ft) high – excellent for growing in borders and formal beds or as cut flowers. But there are dwarf kinds only 23-30cm (9-12in) high which are useful for rockeries and small informal patches in borders near the house so that their scent can waft through the open windows.
Cheiranthus cheiri has had numerous varieties, tall and dwarf, developed from it. The following are some of the most readily available varieties.
‘Blood Red’ has early deep velvety red flowers and reaches 38cm (15in) high.
‘Cloth of Gold’ has large, golden, sweet scented flowers and reaches 38cm (15in) high.
‘Eastern Queen’ has salmon-red flowers and reaches 38cm (15in) high.
‘Fire King’ has bright scarlet-orange flowers and reaches 38cm (15in) high.
‘Ivory White’ has cream-white flowers and reaches 38cm (15in) high.
‘My Fair Lady Mixed’ comes in mixed pastel shades and stands 30-38cm (12-15in) high.
‘Persian Carpet’ comes in a pastel mixture of cream, orange, apricot, gold, purple and rose. It reaches 38cm (15in) high.
‘Primrose Monarch’ has primrose-yellow flowers and reaches 38cm (15in) high.
‘Rose Queen’ has rose-pink flowers and reaches 45cm (18in) high.
‘Ruby Gem’ has rich ruby-violet flowers and reaches up to 38cm (15in) high.
‘White Dame’ has cream-white flowers and is 38cm (15in) high.
‘Dwarf Mixed’ includes a good range of colours and reaches 30cm (1ft) high.
‘Golden Bedder’ has large golden-yellow flowers and reaches 25cm (10in) high.
‘Orange Bedder’ has rich orange flowers shading to apricot, and reaches 25cm (10in) high.
‘Primrose Bedder’ has primrose yellow flowers and reaches 25cm (10in) high.
‘Scarlet Bedder’ has rich scarlet-red flowers and reaches 25cm (10in) high.
‘Tom Thumb Mixed’ has late-flowering blooms in mixed colours; it is only 15-23cm (6-9in) high.
Cheiranthus x allionii, the Siberian wallflower, has had a handful of varieties developed from it. They form neat compact plants with orange or yellow flowers appearing from late spring till early summer.
‘Aurora’ grows 25-30cm (10-12in) tall and bears flowers in shades of orange, brown, apricot and mauve.
‘Glasnost Mixed’ gives 30cm (12in) high plants, with fragrant flowers in a range of pastel colours, including lilac.
‘Spring Jester’ is a seed mixture producing 30cm (12in) high plants with flowers in shades of apricot, orange, golden-yellow, lemon, lilac and occasionally white.
Sow the seeds thinly in a seed bed in late spring to early summer. When the first true leaves appear, thin out the seedlings to about 15cm (6in) apart.
In mid autumn, plant them out in their flowering site, setting the tall varieties 30-38cm (12-15in) apart and the dwarf varieties 25-30cm (10-12in) apart. Most well-drained garden soils are suitable, though acid soils should be dressed with lime. The planting site must be in full sun.
When the plants reach 12-15cm (5-6in) high, pinch out the tips to encourage bushy growth.
Pests and diseases
Cabbage root fly maggots may cause the roots to rot and plants to wilt. Or the plants can become stunted as a result of club root – swellings on the roots.