The colourful but lowly Rock. It is an extremely useful space-filler, rapidly covering large bare patches and bearing a profusion of between May and July. Dead-head regularly and once flowering is over, cut back all straggly .
VARIETIES: The basic details of H. nummularium are height 6 in., spread 2 ft.
Flowering period: May-July. Many named varieties are available, ranging in colour from white and yellow to deep red. The popular Rock Rose has two uncommon alpine relatives which are less invasive. H. alpestre (height 4 in., spread 1 ft.
Flowering period: June-July) bears yellow, bowl-shaped flowers – similar-shaped flowers are borne by the golden H. lunulatum (height 8 in., spread 1 ft. Flowering period: June-July).
SITE AND SOIL: Requires free-draining, non-acid soil – full sun is essential.
PROPAGATION: Plantin a cold frame in summer.