Hit the wallf lowers!
If you want an unrivalled display of colour next spring, then now is the time to act...
YOU might expect a plant with a common name like wallflower to blend into the background, but there’s nothing shy and retiring about this early-flowering gem. Quite the opposite, in fact. Its brightly coloured, scented blooms ensure it is the centre of attention from mid to late spring.
The flowers are borne in dense clusters during April, providing a vibrant spectacle that will last for six weeks or so. They come in many shades of white, yellow, orange, red and purple, and pack a heady vanilla-like perfume with a distinctive spicy kick.
Wallflowers are usually treated as biennials. Bare-root or plug plants are widely available for planting in autumn. They will form strong roots and bushy foliage over winter, followed by buds and flowers in a few months.
When I was young, my mother bought bunches of wallflowers from the local greengrocer, who sold them wrapped in damp, dirty newspaper. Back then, I suspect it was the only place you could get any, but these days most garden centres, DIY stores and online nurseries stock them.
Wallflowers, which are known botanically as Erysimum cheiri, were at the peak of gardening fashion during the Victorian era, when amateur plant-breeders flooded the market with hundreds of showy varieties. A dip in popularity during the 20th Century led to many of these disappearing from cultivation.
Today, about 50 different varieties are available in Britain. ‘Vulcan’ has dark red flowers on 18in stems, while ‘Fire King’ boasts 2ft-tall stalks clothed with burntorange blooms. ‘Ivory White’ makes a compact, bushy plant covered with clusters of creamto-pale-primrose flowers. Dating back to the 19th Century, ‘Harpur Crewe’ possesses strongly scented, double yellow flowers.
If you can’t decide on a specific colour, there are plenty of tempting mixes on offer. ‘Most Scented’ is a blend of colours that have been selected for their potent perfume, and ‘Persian Carpet’ contains a rich blend of cream, rose, apricot, orange, gold and purple. The ‘Brilliant Bedder’ series are the most compact available, with ten stems packed with flowers in red, orange and yellow shades. Apart from bien- nial wallflowers, there are many longer-lasting perennial varieties. These don’t come in as many shades as biennial types and tend to be more lightly scented, if at all. However, they have a much longer flowering period, usually from late winter until early autumn. For my money, king of them all is Erysimum ‘Bowles’ Mauve’. Named after plantsman E. A. Bowles, this shrub-like treasure has bluish green leaves and 30in stems of purple flowers that are a magnet to pollinating insects.
Wallflowers prefer a sunny spot with well-drained soil. They’ll flower their socks off in poor to moderately fertile ground – avoid digging in compost as they tend to be more reluctant to flower if the ground is too rich. Plants are best in alkaline soil, but will do well in all but the most acidic conditions.
Avoid planting them in the same spot as last year or in soil that was previously home to brassicas – cabbages, cauliflowers, sprouts and similar vegetables. These flowers belong to the same family of plants and are vulnerable to club root, a fungal menace that kills roots. Unfortunately, this disease is incurable and can survive in the soil for 20 years.
They are ideal planted alongside paths or as groups at the front of beds and border. Alternatively, mix them with other spring flowers. A classic combination is to plant them with taller tulips. Erysimum cheiri ‘Fire King’ make an excellent partner for purple tulip ‘Queen of Night’, while Erysimum cheiri ‘Cloth of Gold’ looks great with ‘Golden Apeldoorn’ tulips.
Wallflowers can be planted any time from late August until November. Space them 6in apart and inter-plant with tulips in November. This helps to avoid tulip fire, a soil-borne fungal disease that attacks these bulbs. Active earlier in the season, its spores are killed off by cooler conditions. Many gardeners pull up wallflowers once the show is over, although plants can be left in situ.
They’ll keep on going for several years but tend to deteriorate with age, becoming leggy and less floriferous.
Keep plants compact by pruning in early summer – this also results in a later flush of flowers.