Cheilanthes lanosa

Cheilanthes lanosa is a curious fern forming small clumps of evergreen fronds, ranging from 20 to 30 cm (8 to 12in), with a bluish-grey green colour and a woolly appearance. This hardy variety is native to arid regions of the United States and Mexico, where it is naturally adapted to difficult conditions of heat and drought. It can be grown in borders or rockeries, exposed to the sun and in well-drained soil.

Cheilanthes lanosa is a perennial fern belonging to the Pteridaceae family, native to the Southwest of the United States and Mexico. It can be found growing on cliffs and rocky hillsides where it has adapted to extreme heat and aridity. Its resistance to drought is characterised in particular by the silver hairs that cover the fronds, which capture morning dew and limit evapotranspiration during the day. Its species name, lanosa, means 'woolly' in Latin and highlights this hairiness on the fronds. Cheilanthes lanosa forms a clump that reaches about 30 cm (12in) in height and width, and persists throughout winter. The brown stalks bear bluish-grey green fronds on the upper surface, and the reproductive cells (sori), arranged on the lower surface, are rusty in colour. Hardy down to -15°C (5°F).

Cheilanthes lanosa is preferably planted in spring, in full sun or with some light shade, in well-drained and fertile soil, rocky, slightly acidic or neutral. This plant does not tolerate waterlogged soil during winter, so it can be grown in a pot (with well-draining substrate) to protect it from these unfavourable winter conditions. The withered fronds are pruned at the end of winter. It will thrive and look its best in a rock garden or above a wall, and will be in good company with blue fescue, with which it harmonises well both in terms of conditions and colour.

Although these ferns belong to a genus that is widespread worldwide, almost all of them are of tropical origin. Only about ten species (if that) can be cultivated with relative ease in Europe.