Helianthemum nummularium - Rock Rose

Helianthemum nummularium, also known as common rock-rose, yellow rock-rose or coin-leaved rock-rose, is a perennial shrub that flowers throughout the summer in the mountains of temperate Eurasia. Its low and spreading growth is adorned with a dense dark green foliage and covered in truly bright sulphur yellow flowers. In the garden, this rock-rose will naturally earn its place in a sunny rockery, even on limestone soil.

Belonging to the family of Cistaceae, the rock-rose is similar to cistus. Helianthemum nummularium is a widely spread botanical species in Europe and Turkey, found in rocky and limestone terrains in the montane zone. It is a woody-based herbaceous plant that forms a spreading clump, a bit loose, 15-20 cm (5.9-7.9 in) tall and about 30 cm (11.8 in) wide. Its evergreen foliage in winter consists of very small leaves of a shiny dark green colour on the upper side, lighter on the underside. The long flowering period extends from June to September. The plant produces numerous small 3-4 cm (1.2-1.6 in) diameter flowers with 5 petals forming a cup, light yellow with a more golden centre, adorned with a cluster of golden stamens.

Helianthemum means "sunflower" in Greek, an appropriate name for these flowers that only open in the presence of strong sunlight. Its delicate little blooms last only a few hours, but renew themselves constantly throughout the summer.

Helianthemum nummularium is the ideal plant to enhance a rocky garden or sunny slope, cascading over a wall, or in paving. It will also have a beautiful effect in the foreground of perennial borders or raised beds. Cultivating it in pots or containers on terraces also suits it very well. It is perfect for the creation of green walls and green roofs. It can be associated with many other rock plants (Erigeron, Alyssum, Shrubby Wallflower, Aubrieta), as well as perennial plants such as: Lavenders, German Iris, Cistus, Silver Bindweed, or Coreopsis. Its flowers blend delicately with the grey foliage of Stachys, artemisias, ballotas and silver baskets.