Yucca rostrata

Yucca rostrata is sometimes called the Beaked Yucca because of its monumental inflorescence, evoking a giant beak plunging into its spherical head bristling with a thousand leaves of metallic green-grey-blue. It is one of those exotic but hardy plants from the cold North American deserts in winter and arid in summer, which we dream of adopting to bring a touch of exoticism and the breath of wide open spaces to our sometimes conventional settings. Of beautiful stature, it grows fairly quickly in fertile and deep soil, forming a magnificent plant after a few years. Reserve a prime location for it in a dry garden or in the centre of a large rockery, it will be the star!

Originally from the mountainous areas of central northern Mexico, Yucca rostrata is capable of withstanding temperatures of around -16° C (3.2° F) in very dry soil, and long periods of summer drought. It is a shrubby plant belonging to the Agave family, known for its rather slow growth in poor and dry soil. When young, Yucca rostrata forms a hirsute ball, very dense and naturally not very branched. After many years, it can form a trunk, sometimes double, 3 m to 4 m (9.8 ft to 13.1 ft) high, covered with a 'skirt' of dry leaves, up to 30 cm (11.8 in) in diameter. Each trunk bears a large spherical crown 1 m to 1.50 m (3.3 ft to 4.9 ft) wide, composed of a multitude of linear leaves. The green-blue leaves, edged with yellow, are quite rigid, narrow, linear, and end in a spine. They measure 40 cm to 60 cm (15.7 in to 23.6 in) in length and 1.2 cm to 2 cm (0.5 in to 0.8 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 paniculate resembling a wide chandelier. The flowers, bell-shaped and pendulous, have a diameter of 3 cm (1.2 in) and are white and waxy in texture. They are carried in upright and branched panicles measuring 40 cm to 70 cm (15.8 in to 27.6 in), and reaching over 4 m (13.1 ft) in height. These flowers are edible and have a slight sweet taste, which is pleasant in summer salads. When watered during the summer, Yucca rostrata shows spectacular growth.

Yucca rostrata is perhaps the most graceful of all. In the garden, it requires plenty of sun and very well-drained soil. It can tolerate poor and dry soil. It cannot tolerate heavy and waterlogged soils in winter. It suits 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 receive it. It should be kept away from walkways and young children, due to its sharp-pointed leaves. This tall plant will simply be magnificent when isolated, accompanied by a carpet of cerastium, Ceratostigma plumbaginoides, Delosperma, or even a short grass meadow called Zoysia tenuifolia, the Mascarene grass. It can also be planted alongside agaves, prickly pears, and fairly hardy candelabra cacti (Cleistocactus strausii, Cylindropuntia imbricata) and Aloe arborecens. Yucca rostrata makes a dramatic feature when planted in a very large pot on a terrace, right next to a Sesbania punicea and a purple foliage mimosa called Acacia baileyana 'Purpurea': the combination of the texture of the foliage, their colour, and the yellow flowering of the mimosa will be superb in winter, and the marriage of its bluish foliage with the bright orange clusters of the Sesbania will be wonderful in summer. Choose the most sheltered spot, in full sun, and away from foot traffic to avoid contact with its pointed leaves.