Marrubium supinum

The Marrubium supinum, also known as the Creeping Horehound, is a plant related to the mint family with remarkable evergreen foliage and a lovely cushion-like habit, wide and regular. It thrives in dry soil, as the aridity accentuates the fluffy and light appearance of its small leaves. Its pinkish-purple flowering is rather discreet in late spring, but it is sought after by bees. Ideal for dry gardens, rockeries, gravel beds, and dry slopes.

The Creeping Horehound is native to the mountains of southern Spain and is more sporadically found in North Africa. In the wild, it is found on rocky soils, uncultivated land, and roadside areas, up to an altitude of 2,500 meters. This species tolerates summer drought and nutrient-poor soils very well. It has a hardiness rating of -12/-15 °C in well-drained soil.

The Marrubium supinum is a woody-based perennial herbaceous plant that forms a tuft of semi-prostrate stems. At maturity, the plant measures approximately 40 cm in height and 50 to 60 cm in width. Its square-shaped stems are fuzzy and slightly woolly. Its foliage persists in winter in regions that are not too cold. The leaves are rounded, dentate at the edges, puckered, very hairy on the upper surface, and slightly less so on the underside. They measure 2 to 6.5 cm in length and 1 to 3 cm in width, with a soft grey-green colour and a lighter margin. The plant usually flowers between May and June. The inflorescence consists of globular whorls, clusters of flowers measuring 2 to 3 cm in diameter, each containing 16 to 26 pinkish-purple flowers. It is a nectariferous and melliferous flowering plant. By early March, the stems become bare. When pruned, the plant vigorously regrows from its stump.

Marrubium supinum is a fascinating perennial for low-maintenance gardens, thanks to its cushion-like appearance and highly ornamental foliage. It is ideal for dry and hot areas, and it is very useful in rockeries, borders, and sun-drenched flower beds where it forms dense and clear masses. It is an excellent companion for Mediterranean plants such as oregano, thyme, lavender, and rockrose. Its light foliage also harmonizes well with the colourful flowering of bushy salvias and the delicacy of gauras.