Rhododendron ferrugineum

Rhododendron ferrugineum, also known as the Alpine Rose, is a shrub of the Ericaceae family, one of the few native representatives of the genus in Europe. It is found in the Alps, the Pyrenees, and the northern Apennines, where it often forms dense and continuous stands on siliceous slopes between approximately 1,600 and 3,000 meters. It is characteristically absent from calcareous substrates, unlike its close relative Rhododendron hirsutum.

It is an evergreen shrub with a spreading and bushy habit, commonly reaching 50 to 100 cm in height, sometimes more in sheltered conditions. The leaves are persistent, leathery, oval-elongated, dark green, and shiny on the upper side, densely covered with characteristic rusty scales on the underside — it is precisely this feature that gives it its specific epithet and common name.

The flowers, grouped in fairly dense terminal corymbs, are tubular-campanulate, from bright pink to deep pink-purple. In its natural habitat, its flowering extends from June to August depending on the altitude. In cultivation, it generally occurs in May-June. The ability of this species to colonize vast slopes and cover them with a bright pink during flowering is one of the most striking spectacles of the siliceous subalpine zone.

In cultivation, it imperatively requires an acidic, humus-rich, fresh, and well-drained soil, without the slightest trace of lime. It tolerates full sun at high altitudes but appreciates light partial shade in lowland conditions. Perfectly hardy, it is however poorly suited to regions with hot and dry summers.