Brahea armata - Mexican blue palm

The Mexican blue palm, Brahea armata in Latin, is undoubtedly one of the most beautiful hardy palms, capable of withstanding frosts of around -10/-12°C (14/10.4 °F) , or even more if the soil remains dry in winter. It is appreciated for its beautiful crown of almost blue leaves, worn like a bouquet of large fans at the top of a thick trunk, as well as for its spectacular inflorescences, followed by edible fruits. Sometimes, it takes a very long time to be able to admire them, but a young specimen will already have a great impact in a large rockery or in the centre of an exotic bed. Native to arid areas of Mexico, it prefers poor and dry soils and requires plenty of sun and heat to thrive.

Brahea armata (synonym Erythea armata, Brahea clara, Brahea roezlii, Erythea elegans) belongs to the family of arecaceae. It is native to the Northwest of Mexico (Baja California, Sonora), where it is found growing spontaneously in arid places, in gorges and humid canyons where water is available at depth. This palm, which can very slowly reach a height of 10 to 14 m (32 ft 10 in to 45 ft 11 in), is carried by a single, thick false trunk (stipe), sometimes reaching 45 cm (17.7 in) in diameter, grey in colour, bearing the remains of the old dried leaves. These dry leaves form a kind of grey 'skirt', just like with Washingtonia. Its foliage that is arranged in a terminal crown will not exceed 3 m (9 ft 10 in) in width. The base-enlarged stipe gives rise at its top to 25-30 slightly costapalmate leaves, i.e. palmate leaves arranged in a fan around a central axis. Each leaf, 70 cm (27.6 in) to 1.2 m (3 ft 11 in) wide, sports a beautiful grey-blue colour, due to the presence of a whitish waxy film on their upper surface. The lower surface is slightly glaucous in colour. It is divided into 40 to 60 rigid segments and carried by a petiole reaching 1 m (3 ft 4 in) to 1.5 m (4 ft 11 in) in length, covered with brown fuzz on the front, silvery in colour on the back, and bordered by small light brown teeth.

The spectacular flowering occurs on specimens over 30 years old. It only occurs outdoors, in summer and in hot climates, in the form of long inflorescences (up to 6 m (19 ft 8 in)), arched and largely dominating the crown of leaves. The very numerous flowers, white to ivory in colour, are followed by the formation of countless small round fruits, 2 cm (0.8 in) in size, brown and shiny, each containing a smooth and shiny brown seed. These fresh seeds germinate several months after sowing.

Highly valued as a roadside tree in coastal and mild climates, especially dry and hot ones, the Mexcian blue palm forms part – along with Washingtonia robusta and filifera and Phoenix canariensis – of the most commonly cultivated tropical ornamental palm species in temperate countries. Irreplaceable and prestigious in mild climates, it can also be cultivated elsewhere in a large container, which will be stored in a cool, bright, and well-ventilated room during winter. Planted near an entrance, or on either side of a gate, or planted individually near a swimming pool, it will be superb. Like Eucalyptus and large mimosas, in the background of a flower bed, it forms a typical backdrop for gardens bordering the Mediterranean or the Atlantic coast of southern France. Fans of graphic and blue plants can plant alongside it the Siberian Nolina, the Oval-leaved Agave, the Wheeler's Sotol, the Yucca rigida, and other spectacular succulent plants well adapted to arid conditions.