Erysimum ‘Ruston Royal’
This Erysimum was introduced to the Conservation Scheme by the Norfolk & Suffolk Group in 2010. It was a seedling that was spotted in the garden at East Ruston Old Vicarage in Norfolk and is thought to be a hybrid between E. ‘Bowles Mauve’ and a plant from the Canary Island group of erysimums which have the bright green, heavily ribbed and serrated leaves as found in ‘Ruston Royal’.
It is a robust cultivar with strong, woody stems and an upright habit to 70cm, forming an evergreen bush. Flowers are borne on long racemes over several months from May to September, with light and dark mauve flowers that age to a paler lilac. It should be deadheaded regularly to prolong flowering.
Erysimums need free-draining neutral to alkaline soil in full sun. They are short-lived perennials as the stems become woody and older plants can suffer from ‘wind-rock’ which will eventually kill the plant. Trim the whole plant in midsummer to maintain a tidy, compact shape, but to ensure continuity plants should be propagated regularly by inserting tip cuttings into gritty compost where they root easily.
Leaves may be disfigured by flea beetle and slugs and snails may be a problem.
This is a good plant, and was listed by Val Bourne as one of her ‘best wallflowers for spring display’ in Gardens Illustrated April 2013. It deserves to be more widely grown, but is currently only listed by one nursery in the RHS Plantfinder.