Androsace sarmentosa

Androsace sarmentosa, sometimes called Rock jasmine, is one of those pretty alpine perennials that have the gift of dressing stones and occupying the smallest cracks filled with neglected soil left by other plants. Slowly spreading as a very low cushion, it has a very pretty foliage covered with white hairs, which persists in winter, and is adorned in late spring with delicate displays of pink to mauve flowers with a yellow centre. In the garden, it works wonders in alpine rockeries, dry stone walls, or above walls, as long as the soil does not dry out too much.  

Androsace sarmentosa belongs to the family Primulaceae, and is related to primroses. It is native to the Himalayas and western China, where it grows between 2,700 and 4,000 m (9 and 13ft) in altitude. It is a charming slow-growing perennial, forming stems that root upon contact with the ground. Ultimately, it measures 10 to 15 cm (4 to 6in) in height and 35 to 40 cm (14 to 16in) in spread. The leaves, 4 to 5 cm (2in) long, are simple and gathered in compact clusters (whorls) on the stems. They are lanceolate in shape and are dark green-blue enhanced by numerous short white hairs that give the cushion a silver shine throughout the year. The flowers, 7 to 9 mm (1in) in diameter, bloom in June-July, occasionally in August, gathered in small umbels above the foliage. Each flower has 5 light pink to mauve petals well spread around a yellow to red centre. 

Fairly easy to grow in rocky or gravelly soil, but soil that is not too dry, this Androsace finds its place in raised beds, rockeries, on a wall, or on a slope, in association with other similar small plants, which won't risk suffocating it: choose, for example, saxifrages, gentians, or even Edelweiss, which appreciate the same environments. This plant is particularly suitable for alpine rockeries and alpine climates.