Campanula × haylodgensis Yvonne

Campanula × haylodgensis ‘Yvonne’ is a small perennial rock garden campanula whose lavender-blue bell flowers open widely above a cushion of small green leaves. It spreads between stones and flowers from early to late summer. This variety combines the wild charm of alpine campanulas with fairly simple cultivation; it simply needs well-drained soil that remains slightly moist. It is particularly suitable for troughs, walls and borders in sunny to lightly shaded positions.

This herbaceous perennial of the Campanulaceae family is a horticultural hybrid derived from Campanula carpatica and C. cochleariifolia, two European alpine campanulas. In the wild, these species occupy rocky slopes, scree and crevices where water drains away quickly. This cross-breeding was achieved at the Scottish establishment of Hay Lodge at the end of the 19th century, giving rise to the epithet haylodgensis. This parentage explains its intermediate appearance: it has inherited from C. cochleariifolia a very low habit and fine foliage, while C. carpatica has passed on wider, more open bell flowers. The ‘Yvonne’ selection bears single flowers, whereas several older forms of this hybrid, notably ‘Plena’ and ‘Warley White’, are double. The plant develops a compact crown and short, flexible, more or less prostrate stems, forming a carpet 10 to 15cm tall and 20 to 30cm wide. Its growth is not stiff: the stems relax over time and may trail slightly over the edge of a trough or wall. The small, 1 to 2 cm long leaves are rounded to ovate, sometimes heart-shaped at the base, and edged with shallow teeth. Their medium green, slightly glossy colour sets off the flowers well. The foliage is semi-evergreen: it remains dense during mild winters but may partially die back under severe frost. The plant flowers from June to August. Its stems bear clusters of single, rounded bell flowers facing upwards or outwards. Their lavender-blue to violet-blue, 2 to 3cm wide corolla opens into five fairly short lobes. The flowers are loved by pollinating insects. This campanula is very hardy, down to -25 to -29 °C in well-drained soil.

In a rock garden or large trough, plant this hybrid campanula ‘Yvonne’ in a pocket of soil between two stones. Pair it with other small rock garden perennials that will not smother it. For example, Basket-of-gold, Aubrieta, Iberis, Saxifraga paniculata var. minutifolia or Dianthus deltoides ‘Albiflorus’.