'Helene von Stein' is a cultivar or S. byzantina, and is a dense, mat-forming perennial with velvety, soft, grayish white leaves. This cultivar has larger leaves than others and is more heat and humidity resistant. Though reported to not have flowers, eventually, in time, some may begin to appear. The foliage grows to about 8 to 12 inches tall and 18 to 24 inches wide. Use in rock gardens, sunny borders, along walks, and in parkstrips.
Grow in average, dry to medium, well-drained soil in full sun. Drought tolerant. Will tolerate some light afternoon shade, too much shade, however, may impede leaf drying and promote the onset of disease and general mushiness. Avoid overhead watering. Pick off damaged leaves in the early spring, before new growth emerges. Divide in spring or fall. Spreads by creeping stems that root as they go along the ground and can be aggressive in rich soils or in sites that are over-watered. 'Helene von Stein' can be seen at the Washington Square Garden, and the blooms are lovely...