Yucca rigida

Yucca rigida, sometimes called Blue Yucca because of the colour of its foliage, is one of those extraordinary, remarkably ornamental plants from the North American desert areas, that we dream of adopting to bring an exotic colour and the breath of wide open spaces to our sometimes conventional decor. Of beautiful stature, with an almost electric blue, developing a thick trunk topped with a superb ball bristling with a thousand narrow and erect leaves, it naturally imposes itself, forming after a few years a magnificent plant capable of outshining the beauty of all others. Reserve a prime location for it in a dry garden or in the centre of a large rockery – it deserves it!

Originally from the mountainous areas of central North Mexico, Yucca rigida is capable of withstanding temperatures around -15 °C (5 °F) in dry soil, and long periods of summer drought. It is a rhizomatous plant belonging to the agave family, with rather slow growth. When young, Yucca rigida forms a shaggy ball that is very dense and naturally not very branched. After many years, it can form a trunk 3 to 4 m (10 to 13 ft) high, covered with a 'skirt' of dry leaves, up to 30 cm (12 in) in diameter. This trunk bears a large spherical crown 1 m (3 ft) to 1.5 m (5 ft) wide, composed of a multitude of rigid leaves. The very blue leaves are quite short, wide and linear, and end in a strong spine. They measure 40 to 60 cm (16 to 24 in) in length and 1.2 to 2 cm (0.5 to 1 in) in width. Flowering occurs after 3 to 4 years of cultivation. In this species, the inflorescence is unique and partially buried in the mass of foliage. It develops into a large panicle resembling a large chandelier. The flowers, bell-shaped and pendulous, measure 3 cm (1 in) in diameter and are whitish-blue and waxy in texture. They are carried on erect and branched panicles measuring 50 to 80 cm (20 to 32 in) in height, and reaching over 4 m (13 ft) in height. When watered during the summer, this Yucca rigida shows spectacular growth.

Yucca rigida requires a lot of sun and very well-drained soil, or even poor and dry soil. It particularly fears heavy and waterlogged soils in winter. It will find its place on a large arid slope, in the centre of an exotic or contemporary rockery, or even near a swimming pool if the soil is well prepared to accommodate it. It should be kept away from passageways and young children, due to its sharp-tipped leaves. This large plant will be simply magnificent when isolated, accompanied by a carpet of cistuses, Ceratostigma plumbaginoides, Delosperma, or even a short grass meadow such as Korean velvet grass (Zoyzia tenuifolia). It can be combined with agaves, prickly pears, and hardy candelabra cacti (Cleistocactus strausii, Cylindropuntia imbricata) and with equally spectacular and frugal shrubby aloes. It can also be planted in a very large pot on the terrace, right next to a Sesbania punicea and a mimosa with purple foliage called Acacia baileyana Purpurea: the combination of the texture of the foliage, their colour, and the discreet yellow flowering of the mimosa will be superb in winter, and the marriage of its blue foliage with the bright orange clusters of the Sesbania will be wonderful in summer. Choose the most sheltered location, in full sun, and away from walkways to avoid contact with its pointed leaves.