Campanula portenschlagiana 'Catharina'

Common name: Serbian Bellflower 'Catharina'

Description: Campanula portenschlagiana 'Catharina' is a charming, compact mat-forming perennial that produces a generous and prolonged display of upward-facing, star-shaped flowers in a rich violet-blue throughout summer. It forms a low, spreading cushion of rounded, toothed foliage that tumbles attractively over walls, raised beds, and the edges of containers, where the cascading stems become almost completely hidden by flowers at peak bloom. 'Catharina' is a notably free-flowering selection with a particularly tidy, uniform habit, making it one of the best forms available for UK gardens.

Other benefits: prolific violet-blue flowers over a very long season; ideal for walls, troughs, and raised bed edges; evergreen in mild winters; low maintenance

Wildlife attraction: bees and other pollinating insects

Height & spread (approx.) at 10 years: 10–15cm x 40–50cm

Position: full sun to partial shade; walls, rock gardens, alpine troughs, containers, and raised bed edges

Soil pH: neutral to slightly alkaline (pH 6.5–7.5); well-drained soil; tolerates chalk and poor sandy conditions

Moisture: low to moderate; drought tolerant once established; excellent drainage important; dislikes waterlogging

Winter hardiness: fully hardy to -20°C