Campanula portenschlagiana ‘Catharina’ forms an evergreen carpet of heart-shaped foliage that becomes smothered in purple-blue, bell-shaped flowers in summer. A vigorous hardy perennial, this floriferous dwarf bellflower is ideal for rockeries, containers, groundcover, the front of borders, underplanting shrub roses and tumbling over walls, where it will create a stunning display year after year whilst requiring virtually no maintenance. Height: 20cm (8in). Spread: 30cm (12in).