Plant of the Month | Erysimum

Erysimum, more commonly known as wallflowers, are spring to summer flowering plants that provide vibrant displays of colour. Many varieties are hardy perennials and have attractive evergreen foliage, adding structure and aesthetic value to the garden even after the flowers have faded.

These easy to grow plants are perfect for adding colour and fragrance to borders and containers. Position in a sunny spot and enjoy months of flowers, from spring well into summer - and sometimes beyond.


Erysimum Varieties

Erysimum 'Bowles’s Mauve'

This variety is a bushy, long-flowering, vigorous wallflower that produces long stems of purple flowers from early spring to summer and can continue into autumn. It can reach a height of 0.75m if allowed to do so. Its foliage is made up of narrow leaves in a grey-green colour.

Flowering Time: March to August

Sun requirements: Full sun

Soil: Well-drained, moderately fertile soil, preferably neutral or slightly alkaline (erysimums are good plants for chalk soils).

Hardiness: Hardy in free-draining soils. Can be affected by cold winters if the soil is too heavy and wet.

Size: Grows to 75cm height x 50cm spread


Erysimum 'Winter Joy'

This variety produces upright racemes of lilac-purple flowers from late winter into midsummer. It is perfect for a mixed border and copes well in coastal areas. 

Flowering Time: February to July

Sun requirements: Full sun

Soil: Well-drained, moderately fertile soil, preferably neutral or slightly alkaline (erysimums are good plants for chalk soils).

Hardiness: Hardy in free-draining soils. Can be affected by cold winters if the soil is too heavy and wet.

Size: Grows to 80cm height x 40cm spread


Erysimum 'Winter Light'

This lower-growing erysimum variety has bright yellow flowers from mid-spring to the end of summer. This is a perfect plant for a mixed border, bringing plenty of brightness and copes well in coastal areas. 

Flowering Time: March to August

Sun requirements: Full sun

Soil: Well-drained, moderately fertile soil, preferably neutral or slightly alkaline (erysimums are good plants for chalk soils).

Hardiness: Hardy in free-draining soils. Can be affected by cold winters if the soil is too heavy and wet.

Size: Grows to 30cm height x 45cm spread


Erysimum 'Winter Orchid'

This compact variety has dense racemes of orange flowers from spring into early summer, with the flowers gradually transforming to a rich purple as they age, like the changing shades of a sunset. This is a good plant for a mixed border and copes well in coastal areas. 

Flowering Time: March to July

Sun requirements: Full sun

Soil: Well-drained, moderately fertile soil, preferably neutral or slightly alkaline (erysimums are good plants for chalk soils).

Hardiness: Hardy in free-draining soils. Can be affected by cold winters if the soil is too heavy and wet.

Size: Grows to 45cm height x 45cm spread


Erysimum 'Winter Sorbet'

This hardy, upright variety produces flower spikes that emerge burnt orange and mature to lilac-purple from late spring into summer, held on top of linear to lance-shaped dark green leaves. This is a good plant for a mixed border and copes well in coastal areas. 

Flowering Time: March to August

Sun requirements: Full sun

Soil: Well-drained, moderately fertile soil, preferably neutral or slightly alkaline (erysimums are good plants for chalk soils).

Hardiness: Hardy in free-draining soils. Can be affected by cold winters if the soil is too heavy and wet.

Size: Grows to 40cm height x 50cm spread


Erysimum Growing Guide


Planting

When planting your erysimum, first water the plant in its pot thoroughly. Dig a hole in the soil roughly twice the size of the pot. Add some quality multi-purpose compost into the base of the planting hole. Remove the plant from its pot and place in the hole, so that the top of the rootball is about level with the surrounding soil. Refill the hole with a mixture of garden soil and compost.

Erysimum varieties prefer to be planted in well-drained, moderately fertile soil that is neutral or slightly alkaline. If your soil is heavy and wet, add grit and sand when planting to encourage better drainage. This will also help protect the plant during the winter months.

Pruning 

Although wallflowers are known for their copious flowers and long flowering periods, you can encourage more growth for longer by trimming faded and dead flowers. In some southern parts of the UK, they can flower all year long! 

Watering

Water generously when first planting and keep the plant well-watered for the first year.

Protection

In colder areas, or if you have heavy soil prone to waterlogging, you may want to protect with a cloche during the winter months.


Erysimum Planting Ideas

Nepeta ‘Six Hills Giant’ and Forget-me-nots make great combination plants with erysimums, because their striking purple and blue hues perfectly complement the vibrant wallflower colours.

Tulips will stand tall against the smaller wallflower varieties, giving added height to a border or planter. 

Creeping rosemary will provide a fragrant backdrop of groundcover and add a new texture next to the woody grey-green and dark green wallflower foliage.


Erysimum Facts

1. Wallflowers are a member of the Brassicaceae botanical family, commonly known as the cabbage family.

2. Perennial wallflowers are a good source of nectar for pollinators; with their extremely long flowering season they can benefit these invaluable garden visitors most of the year round.

3. Many varieties are found growing naturally growing in wall crevices, hence the name and preference for sunny conditions in well-drained soil. They are just as at home, though, in borders and containers.