Quick Guide: summer, hardy, sun/ Semi-shade, height: 7.5cm/3in, width: 30cm/12in

The common name of Saponaria officinalis - soapwort - gives the hint to its former use as a cleansing herb (the leaves produce a lather in water). This species is too large and invasive for the rock garden, however; S. ocymoides is the one to choose, a vigorous perennial which forms trailing mats of small green leaves. Throughout the summer it bears a profusion of bright pink flowers.

GROWING Plant between autumn and spring in good garden soil in sun or partial shade. Cut back after flowering to encourage further blooms and cut back hard in late autumn.

PROPAGATION Divide and replant the roots or detach underground runners and replant between autumn and spring.

VARIETIES `Compacta', slow-growing, neat habit; `Rubra Compacta', rich pink flowers.

POSSIBLE PROBLEMS Generally trouble-free.