Saponaria ocymoides

Rock Soapwort is a mat-forming semi-evergreen rock plant whose flowers are held in loose sprays at the tips of its mound. Masses of bright pink blooms for a long period from spring into summer, covering it. Easy and vigorous it gradually spreads until reaching any edge from which they can cascade. Sun 15cm.

Thérèse Gaigé, CC0, via Wikimedia Commons