Comfrey 'Hidcote Blue'
Striking nodding flowers are produced in whorls around the top of the stems of this virtually impenetrable ground cover, which is suited to shady areas of the garden. The vigorous roots, like the herbal comfrey, may require root barriers to control spread in some situations.
Cut back after flowering has finished for a new flush of growth if the plant spreads too far. Dig up to maintain your desired boundary.