Erysimum

( ehr - RISS - ih - mum )

At-A-Glance Information

Commonly known as Wallflower or Cheiranthus, this genus of perennials, biennials, and annuals includes species which need full sun to light shade (depending on the species) and have varying water needs. There are many wild and garden-type ornamentals in the genus, most with brightly colored inflorescences of flowers that appear in spring and summertime. Green foliage is typically somewhat sparse and leaves are lanceolate. These plants can serve as seasonal color, subshrubs, groundcovers, or container plants in many different garden settings. Take care when planting these flowers in the landscape, as there is evidence that some species are toxic to mammals, including horses.

Erysimum Species and Varietals

The genus Erysimum includes about 150 distinct species and is a member of the plant family Brassicaceae. The best growing zones for Wallflower vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Erysimum x allionii (Siberian Wallflower)
This is a perennial, but is often grown as an annual or biennial plant. It is best in USDA hardiness zones 3-10 or Sunset growing zones A3, 1-9, and 14-24. They have a branching habit, and get 1-1.5 feet tall and a little wider. In spring, they bloom in profuse fragrant orange or yellow flowers. In mild-winter climates, sow seeds in fall, otherwise, sow in springtime. They need full sun and moderate water. These plants are sometimes sold under the names Erysimum asperum or Erysimum hieraclifolium.

Erysimum ammophilum (Coast Wallflower. Sand-Loving Wallflower)
This rare beach-dwelling species is native to Monterey Bay, The Channel Islands, and the coast of San Diego in California. These plants can be biennials or perennials, and range from a few centimeters to over a foot and a half tall. Flowers are bright golden yellow.

Erysimum arenicola (Cascade Wallflower, Sand-Dwelling Wallflower)
Native to British Colombia, Oregon, and Washington, this species reaches about a foot tall at maturity and produces yellow flowers. These flowers prefer to grow in high-elevation climates. Foliage is green.

Erysimum baeticum (Erysimum linifolium baeticum)
This species is native to southeastern Spain, where it grows in subalpine pine forests. Flowering occurs from the end of May through early July, and flowers are pink-purple with four petals. Foliage is very narrow and almost grass-like, and these plants reach 8 inches to three feet tall, depending on the subspecies. This species grows well in USDA hardiness zones 3-10.

Erysimum caboverdeanum (Wild Carnation, Cravobrabo, Cape Verde Wallflower)
Endemic to Cape Verde, this species forms a small shrub that reaches 24 inches tall when in bloom. Narrow, delicate leaves are green to grey-green and flowers are lilac-colored. These flowers are best suited for USDA hardiness zones 6-9.

Erysimum capitatum (Sanddune Wallflower. Western Wallflower, Prairie Wallflower)
Sometimes mistaken for mustard, this plant is common in North America, and forms a basal rosette of foliage from which flowering stems emerge. Blooms are commonly bright yellow, golden or tangerine in color but can also be red, white, or purple depending on the subspecies grown. Best in USDA hardiness zones 3-9.

Erysimum cazorlense
This interesting species of Wallflower is endemic to mountainous areas in southeastern Spain. These short-lived monocarpic plants produce almost needle-like foliage and purple to magenta flowers with cream to yellow centers. Best in USDA hardiness zones 6-9.

Erysimum cheiranthoides (Treacle-Mustard, Wormseed Wallflower, Wormseed Mustard, Cheiranthus)
Native to central and northern areas of Europe and Asia, this species reaches up to 40 inches tall and produces yellow flowers and flat green leaves. This species is known to be toxic to horses.

Erysimum cheiri (Cheiranthus cheiri, Erysimum x cheiri) (English Wallflower, Aegean Wallflower, Cheiranthus)
This species grows to 2.5 feet tall and 1.5 feet wide, and is a perennial in USDA hardiness zones 4-8 zones 4-6, 14-17, 22 and 23 (but is usually grown as an annual or biennial). It is native to Southern Europe and is at its best in cool, moist areas. It has a branching, woody habit with bright green leaves and showy blooms. Flowers are sweet-scented and come in yellow, cream, orange, red, brown, or burgundy and are sometimes veined with darker colors. Blooms pop in springtime, but under ideal conditions it can bloom year-round. Seeds should be sown in spring, or plants set out in fall or early spring. Can self-sow, and needs regular water. This species is known to be toxic to some mammals.

Erysimum franciscanum (Franciscan Wallflower, San Francisco Wallflower)
This species of Wallflower is endemic to the California coast ranging from Sonoma to Santa Cruz counties. Flowers are cream-colored to yellow and bloom from late winter to spring. These plants love sandy soils and are commonly cultivated in gardens as ornamentals. These plants grow well in USDA hardiness zones 9-10.

Erysimum spp. Hybrids and Cultivars (Erysimum x hybrida) (Hybrid Wallflower)
These species are mainly perennials and grow in USDA hardiness zones 6-9 or Sunset growing zones 4-9 and 14-24. Popular selections are described below. All have moderate water needs.

'Apricot Twist'
With fragrant, bright apricot blooms.

'Blood Red'
Bushy, upright grower with deep red blooms.

'Bowles Mauve'
3 feet tall and 4-6 feet wide, with narrow gray-green leaves. Mauve flowers.

'Bredon'
Large yellow flowers and dark green foliage. A compact cultivar.

'Compact Bowles Mauve'
Half the size of its' big brother, but with the same characteristics otherwise.

'Constant Cheer'
Classic cultivar with brick-pink to magenta flowers. In flower for many weeks.

'Fair Lady'
Seed mix with various flower colors.

'Golden Jubilee'
With bright lemon-yellow blossoms.

'Ivory White'
This cultivar produces cream-colored blooms.

'Jacob's Jacket'
Spreading, low habit with a mix of brick red, pink, and dark orange flowers.

'Lemon Zest'
8-12 inches high and just as wide. Pale yellow blooms pop in early spring.

'Night Skies'
Compact, bushy plant with pale peach to lavender flowers.

'Parrish's'
With multicolored flowers in brick-pink, mauve, butterscotch, and violet.

'Pastel Patchwork'
This cultivar produces pink, mauve, and peach flowers. Leggy habit, trim back often.

'Persian Carpet'
Clusters of mixed cream, gold, orange, dark red, and purple blooms.

'Red Jep'
With dense racemes of fragrant orange to brick red flowers.

'Ruston Royal'
With an upright habit and dark mauve flowers.

'Sweet Sorbet'
Lilac-pink flowers bloom on a 14-18 inch tall plant.

'Walberton's Fragrant Star'
With cream-edged foliage and bright lemon-yellow flowers.

'Wenlock Beauty'
2 feet tall and wide, with flowers that vary from brownish to purple in a single spike.

'Winter Orchid'
Compact, mounding habit with

'Winter Passion'
Cultivar with red flowers and a mounding habit.

Erysimum insulare (Erysimum suffretescens) (Island Wallflower)
This perennial is native to the central and southern California coastline, and grows best in USDA hardiness zones 9-10 or Sunset growing zones 14-17 and 22-24. The base of the plant is woody, and gets 6-24 inches tall and 4-12 inches wide. Orange-yellow flowers are fragrant and bloom in spring. Needs little water.

Erysimum jugicola (Alpine Wallflower)
This species is native to the western Alps where it prefers to live in cliffs, dry meadows, and stony pastures. Individual plants reach just under 10 inches tall and produce golden yellow slightly fragrant flowers from July through August. This species is suited for growing in USDA hardiness zones 4-8.

Erysimum kotschyanum (Kotschy's Wallflower)
This perennial species grows best in USDA hardiness zones 5-10 or Sunset growing zones 3b-11 and 14-21, and is treated as a winter annual in hot-summer climates. Leaves are light green and form a mat 6 inches tall and a foot wide. Spring flowers are deep yellow and fragrant. These plants are great for rock gardens and for in between pavers. Divide clumps in fall, and provide the plant with moderate water.

Erysimum menziesii (Menzies' Wallflower)
This rare species is endemic to California, where it grows in sandy dune habitats in Monterey, Humboldt, and Mendocino Counties. These plants are perennials or biennials and do not commonly reach over 6 inches tall at maturity. Flowers are bright golden yellow and bloom in spring and summertime.

Erysimum nevadense (Sierra Nevada Wallflower)
Native to the Sierra Nevada of Spain, this species is biennial or perennial and reaches about 10 inches tall at maturity. Flowers are yellow, and foliage is greyish-green and hairy. This species grows well in USDA hardiness zones 5a-8b.

Erysimum linifolium (Alpine Wallflower)
This shrubby plant is best in USDA hardiness zones 5-9 or Sunset growing zones 4-6 and 14-24, and gets to 2 feet high and 2-3 feet wide at maturity. Cultivar 'Variegatum' is valued for its gray-green foliage edged in creamy white. Flowers are mauve and bloom from spring to fall. This species requires moderate water in the garden.

Erysimum repandum (Spreading Wallflower, Spreading Treacle Mustard, Bushy Wallflower)
This perennial species is native to Eurasia but has naturalized in many other areas of the world. These plants grow well in disturbed soils, and is a commonly seen roadside weed. These plants reach under 2 feet tall when mature, and have a bushy habit with lanceolate green foliage and yellow flowers.

Erysimum scoparium (Teide Wallflower)
This shrubby species forms a rounded small bush with stiff leaves. Native to the Canary Islands, these plants produce purple-pink flowers and prefer to grow in mountainous areas, dry habitats, and in pine forests.

Erysimum teretifolium (Santa Cruz Wallflower, Ben Lomond Wallflower)
This species is endemic to Santa Cruz, California, and is considered to be critically imperiled due to habitat destruction and fire suppression activities in its native range. These are perennial to biennial plants that produce yellow to orangey flowers.

Caring for erysimum

Take care when planting these flowers in the landscape, as there is evidence that some species are toxic to mammals, including horses. Erysimum are considered to be easy-care flowers, and are commonly chosen for garden cultivation for that reason. They thrive in a spot in the garden that receives full sun. They can tolerate partial shade, but have a tendency to become leggy and not flower as well in this exposure. Ideally, these flowers should be getting between 6 and 8 hours of sun each day. Gardeners in warmer climates should provide them with some late afternoon shade. Well-draining soil is essential, with a moderate fertility and a pH of between 7.0 and 9.0 (neutral to alkaline). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Erysimum can be grown in either the ground or in containers.

Fertilize yearly in early springtime with a application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Deadhead flowers regularly to maintain a neat plant and in springtime, prune stems back by at least half to prevent legginess. In cooler climates prune plants back to just a few inches above the soil in fall after flowering has finished. These flowers are generally short-lived perennials or biennials, living for 2-5 years in the garden before needing to be replaced.

Propagation

Erysimum, or Wallflower, can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Wallflower, follow the instructions below:

Propagating Erysimum by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more portion(s) of the end of a non-blooming branch and strip all but 3-4 leaves. Each cutting should have at least one leaf node. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new Wallflower.

Propagating Erysimum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed pods on Erysimum plants are pretty easy to spot, they're large and dangle from the branches, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 1-3 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.