Primula are herbaceous or semi-evergreen perennials, forming a basal rosette of simple leaves, with salver-shaped or bell-shaped flowers which may be solitary or carried in an umbel or in whorls on an erect stem
'Crescendo Blue Shades' is a short-lived perennial to 25cm, usually grown as an annual, forming a rosette of oblong leaves, with erect stems bearing an umbel of large blue flowers with conspicuous yellow eyes