|Official Plant Name||Erysimum|
|Plant Type||Perennial / Annual / Biennial Flower|
|Native Area||South Asia, Europe, Africa, Micronesia, North America – through Costa Rica|
|Flowers||Fragrant four-petalled flowers|
|When To Sow||February, March|
|Flowering Months||March, April, May, June, July, August, September, October, November|
|When To Prune||October, November|
Exposed or Sheltered
0.5 – 1M
0.5 – 1M
March – November
Chalk, loam, sand
Alkaline / Neutral
Erysimum is one of the most under-rated of all flowering plants. Commonly known as ‘Wallflower,’ this delightful plant has everything going for it. It is fairly disease-free, is low-maintenance, and is as at home by itself in a pot on a patio as it is with a motley crowd in a large bed. As for those vibrant blooms, they’re no ‘wallflowers;’ they’re dazzling knockouts!
If ever a flower was hopelessly misnamed, it is the ‘Wallflower’. Pretty, petite, vivid, and fragrant, Wallflowers are more like a gaggle of competing, would-be May Queens on the dance floor. Really, it seems ironic to call such a plant a ‘Wallflower’.
Erysimum is quite a varied genus comprising of annual, biennial, and perennial plants. As herbs and sub-shrubs, they are dainty little things individually but make for a lush carpet collectively. They make excellent bedding choices but are also genuinely ornamental flowering plants in their own right.
Many species flower abundantly from early spring to late summer, and some even dazzle with autumn blossoms. The small four-petalled flowers usually occur as racemes. Their colours include white, cream, yellow, orange, red, and purple, many of which are of a vibrant hue. Besides being colourful, the blooms are also sweet-scented and are attractive to bees, butterflies, and other pollinators. Their foliage too is pleasing to the eye, being in the main of a chalky green colour with a bluish tinge. The daintiness of the stiff, narrow, lance-shaped leaves makes for a fine match to the flowers, and complement them wonderfully well.
Erysimum sub-shrubs are sometimes grown as upright plants by themselves while herbaceous Erysimum varieties – besides the sub-shrubs – are grown in beds, and often occur in their native habitats in clumps and gently swaying mounds. If Wordsworth had come across these lithe, joyful flowers on a summer day, he well may have penned that line, “tossing their heads in sprightly dance” about Erysimum.
And talking about summer dances and May Queens, surely the popular R&B song ‘The Wallflower’ has been played at many a dance. But think about this: does a ‘Wallflower’ get hit with a line like, “Hey, baby! What do I have to do?” And would she ever seductively respond with, “You Gotta Dance With Me, Henry!”?
Yes, that name is ironic. Ain’t no way our ravishing Erysimum is a ‘Wallflower’!
Background and Origins
Erysimum originated about 2 million years ago. It is thought that this plant was introduced to Britain during the Norman Conquest or shortly thereafter by returning Crusaders. That species was Erysimum cheiri and it is now widespread in the U.K. It is the parent species for the vast majority of British cultivars.
Wallflowers are members of the mustard family, Brassicaceae. Similar to mustard and rapeseed plants, they manufacture phytochemicals that repel insects which would otherwise feed upon the flowers. All said, there are over 200 generally-accepted species with up to 272 all said – and that does not include cultivars! In height these plants range from as high as 80 centimetres, e.g. Bowles’s Mauve, down to about 22 centimetres which is the size of some dwarf species native to the Alps.
Erysimum species, hybrids, and cultivars are widely used in public parks and formal gardens. They are used as companion plants, as bed displays, to create blocks of colours, and to make patterns. As for those garden paintings of clocks and heraldry symbols that one sees, Wallflowers are a common component.
The Wallflower has a pleasant (or unpleasant, depending on your point of view) proclivity to take root in the interstices of bricks and stones of a wall, hence its colloquial and common name, ‘Wallflower.’ In a very literal sense this flower grows from and on walls. It is a not-uncommon site on the stone ramparts of old castles and brick walls in the British Isles.
It is hardly possible to do justice to such an interesting and diverse genus in a single article but here is a ‘Sweet 16’ List of this sweet-scented plant. In our quick tour of Erysimum species we must start with E. cheiri and E. Bowles’s Mauve. E. cheiri is the ‘original’ species from which most British varieties descend, as mentioned, and Bowles’s Mauve is probably the most popular cultivar.
E. cheiri aka Aegean Wallflower is native to the Mediterranean region but is now a common sight in the United Kingdom. Though a perennial, it is treated as a biennial. This fairly tall species bears spikes of scented flowers in clusters. Their colour varies from a merry golden-yellow to deep orange.
E. ‘Bowles’s Mauve’ flowers from early Spring through mid-Autumn which is one of the reasons it is valued. The petals are delicate and slightly wrinkly. The colour varies from a pale lilac to a solid mauve. The greyish-green Lanceolate to Linear leaves provide attractive and virtually evergreen foliage.
E. ‘Ivory White’ is a cultivar of E. cheiri. The plants are small and bushy. The rich, creamy ivory white shade of the flower is a soothing tonic for human eyes and the flower itself is a literal tonic for bees which make a ‘beeline’ for these blooms. These plants are ideal for edging and bordering.
E. scoparium is a species native to the montane areas of the Canary Islands. It is an erect shrub with very attractive flowers in shades of lilac and pale purple. However, the distinctive feature about this species is that both the leaves and the petals are a perfect match for each other, being very narrow; among the narrowest in this genus.
E. menziesii – if you can find it. It is a rare and endangered species found in a dwindling location in California. Its foliage is as unusual as the plant; the leaves are very dark and satiny. The floral petals are distinctively shaped, being rounded and slightly convex, and are of a buttercup hue.
E. ‘Golden Jubilee’ is one of the more popular cultivars and if you can’t find E. menziesii, you can use this one as a sub because the flowers are somewhat similar both in shape and in hue. Where it varies is that this is a clumping, robust species that you’ll have no trouble finding and maintaining.
‘Western Wallflower’ species are relatively tall for Erysimum. While E. asperum is native to the American Mid-West in the wide open prairies, related species E. capitatum is found further north in the North-West and Canada. The flowers are borne on longish, stiff stalks. Their petals are wide open almost in a single plane, giving the flower an innocent, frank look. Their hues, ranging from bright and deep yellow to a mellow orange, add to their appeal.
E. pallasii aka E. redowskii is one of the hardiest species for it is native to Russia’s northernmost regions, Greenland, and North-Western Canada. It has a woody stem and oblong leaves. The flowers are petite and have eye-catching mauve to deep purple hues that are very striking against the plant’s foliage.
E. baeticum and E. cazorlense flowers have virtually the same hue as those of pallasii but the resemblance ends there. The petals are narrower and more separated; as for the plants, they are endemic to sunny Spain! They are profuse bloomers; however, the Linear leaves are also points of interest as they are nearly as long and narrow as grass blades.
E. ‘Night Skies’ is a profuse bloomer that can flower until autumn. The waft of their sweet scent will attract bees to your garden. The full petals partially overlap in a whorl. As for the colour, its gentle, soothing tones vary from a perfect baby pink through lilac.
E. ‘Red Jep’ is a popular perennial. Bushy, verdant lanceolate foliage sets off the flower perfectly, which features very full, imbricated petals that are typically of a purplish-scarlet tone but can vary from red to purple. Their fragrance draws bees. It grows to about 30 centimetres.
E. ‘Blood Red’ is twice as tall as E. ‘Red Jep,’ reaching a height of 60 centimetres; what’s more, it’s hue is probably ten times as intense. The full petals are wide open and valvate. No cultivar can be more aptly named, for while the hue is in various tones of deep red and crimson, you will often find it in a perfect ‘blood red.’ This one’s not for the faint of heart!
E. ‘Constant Cheer’ is a very popular variety and is so named because it blooms ‘constantly’ through spring and summer. It is a small evergreen perennial with grey-green lance-like leaves. Their flowers spread ‘cheer’ through their happy tones of orange, pink, mauve, and purple.
E. linifolium ‘Variegatum’ is one of the unusual Wallflower varieties that takes its name from its ‘variegated’ foliage. The lanceolate leaves of this perennial are bicoloured; they have a distinct, fairly thick, border of cream-yellow enclosing a mid-tone green. The intense mauve-to-puple flowers are both striking and very fragrant, doubling – or trebling – this hybrid’s charms.
E. ‘Fair Lady’ could just as well be called ‘Variegatum’ because of its flowers. Yet that would be an understatement. This petite sub-shrub’s flowers simply dazzle. Their pallete is remarkable, ranging from pastel creams and pinks to brilliant vermilion and hot purple. Best of all, frequently the floral petals themselves are variegated, occurring in tones of cream, yellow, pink, and orange.
E. ‘Persian Carpet’ is another variety with multi-coloured and even ‘variegated’ flowers, but this one’s a dwarf variety. The scented flowers have broad rounded petals and occur in hues of cream and yellow through vermilion and scarlet and even purple. Sometimes, petals are bi-toned, have streaks, or are clearly gradated, adding to their visual appeal.
Habitat & Growing Conditions
Erysimum species occur very widely nearly throughout Europe, Asia, and North America. Their range is so extensive that it would be easier to mention the regions to which they are not native or introduced. These few regions comprise of India through Indonesia and a small slice in the east of Canada. Otherwise it is found from Greenland down to Central America and Iran. Varieties are native to Canada, for example E. pallasii and E. capitatum, and even Northern Africa, for example E. nervosum and E. Tourn. ex L.
Most species are best suited to soils that are dry and very well drained with pH ranging from neutral to mildly alkaline. Most prefer full sun but can make do in partial shade.
In the main their hardiness falls between USDA Zones 6 and 8. The hardiness zones of nearly all cultivars also ranges from Zones 6 to 9. However, a few species native to Northern climes are hardy below USDA Zone 6 right down to Zone 3. As is widely known, Erysimum ‘perennial’ species are usually grown as annuals but this is necessary only in the colder zones. They are really perennial when grown in USDA Zones 9 and 10.
Feeding, Care & Growing Tips
One of the many great attributes of Erysimum is that it is a low-maintenance plant that makes do with what little it gets. Though this does not mean that it should be neglected, this happy plant is ideally suited for busy lifestyles that leave little time for gardening.
Depending on the particular species or cultivar, Wallflowers can be grown virtually the year round but mid-Spring and late-Autumn are the best times to grow from seed. Plant seeds outdoors in beds in the middle of Spring, or indoors in late Autumn in containers so that young plants are ready to be transplanted outdoors in mid-Spring.
Seeds may be gently pressed in or covered with a thin layer of soil, and watered. When planting indoors be aware that germination of these seeds requires light.
Erysimum can also be propagated via cuttings. May and June are the best months to do so. Take a cutting so that it has one or two leaf nodes and has no flowering shoots or buds, otherwise remove all flowers and excess foliage bar 3 to 4 leaves. Put the cutting in a slightly richer, loamier soil than normal for this plant.
Erysimum plants really do not need fertilizer – within the Plant World these diminutive things are real troopers! A small amount of slow-release 10-10-10 fertilizer can certainly be given to them as a special treat.
It should be kept in mind that what is written in this section and the following ones does not and cannot apply to Erysimum as a genus – it has over 200 species that are native to very different geographic locations. The advice and recommendations given here apply only to the species, hybrids and cultivars commonly found or grown in the United Kingdom.
Where to Plant Erysimum ‘Wallflowers’
In the United Kingdom, Erysimum should be planted where it can get full sun or sun with partial shade. In general it is best placed in loose chalky and sandy soils that are not overly rich nor moist. Soil must have very good drainage. You can’t go wrong with slightly alkaline soil.
In general, a good mix of different Erysimum species will provide a fantastic splash of brilliant colour in spring and summer.
Wallflowers are among the best put-anywhere plants. Choose from the varieties listed above for beds, borders, and even accents in rock gardens. They are perfect for flower pots on parapets and hanging baskets on balconies.
Many varieties self seed, so once grown, you can just let these plants renew themselves in your garden.
Erysimum should be deadheaded regularly as this will promote more frequent flowering. If you want your bedding Wallflowers to grow in bushy mounds, pinch off the tips when the plants are young.
Although you can trim and prune Erysimum perennials, this should be done lightly and carefully. Severe pruning cannot be tolerated by these plants. If you do prune, trim new growth from the top. Do not trim any woody stems. Mid-Autumn is a good time to prune.
Common Diseases & Problems
The most common problem Wallflowers face are slugs and snails. Slugs are nocturnal so you may have a slug problem without being aware that the damage being caused to your plants is from slugs. A variety of slug-control methods have been devised, from beer traps and diatomaceous earth to microscopic nematodes.
The other main worry is downy mildew, which is tough to combat. Promptly remove all affected parts and ensure that the plant is not crowded in by other plants and has plenty of sun and air.
Where to Buy
Wallflowers used to be a ‘perennial’ favourite at nurseries and garden centres. Though this marvellous plant seems to have fallen out of fashion – evidently without any reason – numerous species and cultivars are still widely available in different forms – seed packets, bare-root bunches, seedlings, and potted plants. They are also available online and by mail order. Perhaps they are on the comeback trail (Amen!).
The most widely- and commonly-found varieties are Cheiri, Bowles’s Mauve, Bredon, Apricot Twist, Constant Cheer, Red Jep, Golden Jubilee, and linifolium Variegatum. But that’s just for starters; you should be able to find several more varieties depending on the seller you visit or locate online.
Fun Facts – Medicinal Uses
Several centuries ago E. cheiri used to be valued for its curative and healing properties in Europe, and such is the case to this day in some countries. Back in Mediaeval Times this plant was named in many pharmacopias including the well-known Materia Medica from the First Century.
E. cheiri is still used for medicinal purposes in South-Central Asia. It is used in Turkey as a treatment for the flu.
E. cheiranthoides is used in Chinese medicine and was prescribed in Europe as late as the 16th Century. Chinese scientific papers suggest that it is effective for cardiac and digestive ailments.
The Navajo Native Americans used to drink infusions of parts of E. capitatum for muscle aches and abdominal pain.
Other species are still used medicinally in various countries, e.g. Ukraine.