Culture
Best grown in dry, alkaline, rocky or sandy, well-drained loams in full sun. Foliage is evergreen, but plants are not reliably winter hardy throughout USDA Zone 5 where they appreciate a winter mulch (preferably a cover of evergreen boughs). Plants prefer cool summers and warm winters, which makes them less than ideally suited for the St. Louis climate. Shear plants after flowering to shape and to encourage additional growth. If grown as a ground cover, space 2-3’ apart.
'Rhodanthe Carneum' reportedly has better heat tolerance than many other sun rose cultivars.
Noteworthy Characteristics
Helianthemum is a genus of about 110 species of evergreen or semi-evergreen shrubs from North and South America, Asia, Europe and North Africa, particularly around the Mediterranean.
Genus name comes from the Greek words helios meaning the sun and anthemon meaning meaning a flower.
‘Rhodanthe Carneum’ is a sun rose cultivar that is synonymous with and often sold as H. ‘Wisley Pink.’ It is a low-growing, woody-stemmed, shrub-like plant with evergreen foliage. It typically grows 6-10” tall and spreads by creeping stems to 3’ wide. Five-petaled, rose-like flowers (to 1” diameter) bloom for up to 2 months (late spring to early summer) in terminal cymes. Flowers are clear pink. Each flower opens for only one day, but in the proper environment, bloom can be so profuse as to cover the entire plant to the point of obscuring the foliage. Grayish-green, lance-shaped leaves (1-2” long).
Problems
No serious insect or disease problems. Rots easily in poorly-drained soils.
Uses
Rock gardens, borders and ground cover. Sprawls exceedingly well over stone walls or dry, sloping ground.