Helianthemum Sulphureum Plenum - Rock Rose

Helianthemum 'Sulphureum Plenum' is one of the brightest hybrid rockroses. Adorned with small double flowers in sulphur yellow pompoms, this evergreen subshrub with a lovely spreading habit is an effective ground cover in rockeries or poor slopes. Perfectly hardy, it is also not demanding in terms of water, but thirsty for sunlight. 

Belonging to the cistus family, Helianthemum is similar to Cistus. Helianthemum 'Sulphureum Plenum' is a common hybrid in horticulture, derived from H. apenninum, native to Southern Europe, and H. mummularium, widespread in Europe and Turkey. 'Sulphureum Plenum' loves limestone and rocky soils and sunlight, forming a low-growing subshrub, with a spreading tuft, a bit loose, 15cm (5.9in) tall and about 30cm (11.8in) wide. Its evergreen to semi-evergreen foliage in very cold regions is composed of tiny linear, opposite leaves, in a rather dark greyish-green colour. It showcases its abundant and bright pale yellow flowering. From May to August, it is covered in a multitude of small double flowers, 2-3cm (0.8-1.2in) in diameter, in cups, with a more golden centre, adorned with a bouquet 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 flowers last only a few days, but constantly renew throughout the summer, even until autumn.

Helianthemum is the ideal plant to enhance a rocky garden, a sunny slope, cascading on a wall, in paving ... It will also be very effective at the front of perennial borders or raised beds. Growing in pots or containers is also very suitable for terraces. It is perfect for the creation of green walls and green roofs. It can be associated with many other rock plants (Erigeron, Alyssum, Carnation, Aubrieta), but also with perennial plants such as: Lavender, Iris germanica, Cistus, Helenium, Convolvulus cneorum, Coreopsis, Agapanthus. Its flowers blend delicately with the grey foliage of Stachys, Artemisias, Ballota, silver baskets ...