Dig It – April Tips from the Secret Gardener

Red Admiral on Wallflower (Steve Maskell)

Last weekend the weather brightened in the south and the garden called out to be tidied up after being left all winter. There were a few casualties of the icy blast, so some scattered spaces have opened up for new plants. Colourful flowers are needed to lift the spirits on any remaining drab days and feed the busily foraging bees.

Only one butterfly - a Small Tortoiseshell - has paid a fleeting visit so far even though the Heather, Rosemary and Primroses have all burst into flower along with shrubs such as the deliciously scented Viburnum ‘Anne Russell’ and delicate Fuji Cherry ‘Kojo No Mai’.

orange-tip (Josie Latus)However, the star plant which has been flowering without stopping, since it was planted couple of years ago, is the Perennial Wallflower Erysimum ‘Bowles Mauve’. This compact evergreen sub-shrub has stems of around 75cm high topped with spires of four-petalled flowers. After a summer of drawing in the butterflies, its lovely mauve flowers were still standing strong through the wind, rain and snow – very impressive indeed.

Sadly, this vigour might only last for only a few more years as these are short lived perennials surviving for two to four years. The constant flowering is due to the fact that they are usually sterile and rarely produce seeds. Luckily they can be propagated fairly easily from cuttings. Although a member of the Brassica family, slugs and snails do not seem to like them much.

E.Apricot DelightThere are numerous Erysimum cultivars available in a wide range of beautiful colours. In addition to E. ‘Bowles Mauve’, some of the common varieties that you might find at a garden centre are E. ‘Winter Orchid’ with orange flowers turning purple, E. ‘Apricot Delight’ with orange flowers and the yellow-flowered E. ‘Walberton’s Fragrant Sunshine’. These are all scented and flower through spring and summer. Keep removing the faded heads to encourage more flowers. All Erysimum need well-drained, neutral to alkaline soil in a sunny, sheltered spot as they are prone to wind-rock, which lets damp and disease get at the neck. They are excellent at the front of a border or in pots.

There are also lower growing alpine varieties in flower now, such as E. Golden Jubilee, which has yellow flowers and suits borders, rockeries, gravel gardens or containers.

Finally, mention should be made of the biennial ‘English Wallflower’ E. cheiri, from which many cultivars are derived. Biennials establish themselves as plants in their first growing season and flower in the second – if you sow them in May/June and plant them in September they will flower the following spring.

E. cheiri is native to southern Greece and the Aegean but was introduced to the UK centuries ago. It has fragrant yellow-orange flowers which are produced in short spikes in spring. There is a story that it was often planted on the walls of castles and manor houses so that the scent could waft through the windows of the bedchambers. It can still often be seen growing in the lime mortar of ancient ruins and buildings such as abbeys.  

Erysimum is a fantastic nectar source and  looks great in combination with many other plants such as Forget-me-nots and Tulips in spring and Shasta Daisies in summer. Let me know which butterfleis they attract into your garden.

Happy Gardening!

The Secret Gardener