A native of the European Alps, rock soapwort is a low growing plant that scrambles over rocks and trails over walls. It’s semi-evergreen foliage forms dense mats and can be used in rock gardens or between stepping stones to advantage. This easy to grow plant is excellent as a ground cover or edging too. The leaves provide an olive green background for the pink flowers that are produced in loose clusters in late spring to late summer. A close haircut after flowering keeps the plant tidy and vigorous. True to their alpine heritage, rock soapworts like cool temperatures and die out in humid areas so it is not a plant for areas south of zone 7. The common name soapwort comes from the fact that the leaves of a closely related plant, common soapwort, produce a thick juice that can be used to make soap.
Type: Herbaceous perennial
Bloom: Loose clusters of small pink flowers are produced in late spring to early summer.
Foliage: Flat, one inch long, olive green leaves are semi-evergreen.
Size: 6-9” H x 7” W
Light: Full sun
Soil: Lean to average, well-drained
Hardiness: Zones 2-7
Care: Prune hard after flowering
Pests and Diseases: None of significance; plants do not tolerate winter rains
Propagation: Seed (stratify seed for 4-6 weeks at 40 F); terminal cuttings, division
Companion plants: Artemesias, speedwells, daylilies, yarrows, sedums.
Outstanding Selections:
var. alba (pure white flowers) var. splendens (large, rose flowers)