Quick Guide: summer, hardy, full sun, height: 15cm/6in, width: 30-60cm/12 - 24in

The speedwell family includes six alpine species but two of these, Veronica pectinata and V. filiformis, are invasive. All bear pink or blue flowers in late spring or summer and are excellent on dry walls or as ground cover plants for rock gardens.

GROWING Plant in a sunny position in well-drained soil from autumn to spring.

PROPAGATION Divide all species, except those that are invasive, in spring, and replant immediately.

SPECIES V. gerrtianoides, slender spikes of palest blue in spring; V. prostrata , dense spikes of pale blue flowers freely carried in early summer; named varieties include `Pygmaea', only Scm/2in high, `Rosea', deep pink and `Spode Blue', china blue; V. cinerea, mat-forming, with grey-green leaves and clear pink flowers, mid-summer; V. teatcrium, variable species - choose named varieties such as `Shirley Blue', deep blue, or `Trehane', light blue with leaves variegated yellow.

POSSIBLE PROBLEMS Powdery mildew.