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Plant of the month: perennial wallflower

Who doesn’t love a plant that is almost too easy?

Erysimum 'Bowles's Mauve'The perennial wallflower Erysimum is well-behaved and can be in flower for nearly the whole year, but in April it is in its prime. There are several cultivars available, but ‘Bowles’s Mauve’ has the Award of Garden Merit (AGM) and pride of place in a special corner of Wisley, Bowles’ Corner.

As a member of the brassica family, this plant is related to cabbages. You can tell this by the glaucous grey foliage, and the familiar flower shape - if you’ve ever had your vegetable patch run to seed, or seen the pretty little lawn weed Cardamine pratensis, or cuckoo flower. This wallflower’s foliage is evergreen which gives a year-round presence in the garden as a bonus, and the stems are strong so it can hold its own against the weather.

Erysimum 'Bowles's Mauve'The flowers are pale mauve initially and darken a little with time. Snip off the spent stems to keep the plant tidy, but it rarely sets seed.

Erysimum ‘Bowles’s Mauve’ will reach up to 75cm tall and will generally last in good condition for a few years, but as it might become top heavy, be prepared to replace it every three or four years.
At Wisley, this plant is in the middle of Bowles’ Corner. The connection is plantsman E A Bowles, a former vice-president of the RHS who had a passion for botanical curiosities.

We grow it in dappled shade, although it is happy in a wide range of garden situations – it even makes a great container candidate. Its purple tones mean it teams well with oranges and lime greens – we have it alongside hellebores, euphorbias and the fresh new orangey foliage of Acer palmatum ‘Katsura’.

One last thing… just to demonstrate the garden-worthiness of this plant it was shortlisted for the Chelsea Plant of the Centenary for the decade 1973-1982 when the RHS Chelsea Flower Show celebrated its centenary a few years ago (it was first shown in 1982 so just scraped in). Enjoy.

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The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.