Dasylirion glaucophyllum - Sotol

Dasylirion glaucophyllum is a persistent tree-like plant that is quite spectacular, related to yuccas and agaves. Its remarkably architectural silhouette, the way light plays through its spherical crown bristling with thin, long, very stiff leaves bordered with white spines, truly impacts a mineral, dry garden, or even the terrace or patio when placed in a jar. This fascinating plant creature bears at the top of a short trunk a kind of giant sea urchin of a beautiful glaucous green colour, a little greener in the centre. Mature specimens flower in a spectacular way, in the form of a huge floral spike that can exceed 4m (13 ft 1 in) in height. It is an easy plant to grow in arid, poor, even limestone soil. Its hardiness depends mainly on soil drainage.

Native to rocky hills and mountainous areas in northern Mexico, Arizona, and Texas, the Dasylirion glaucophyllum is able to withstand temperatures of around -8°C/-10°C (14 °F) in well-drained soil in our French gardens subject to winter rains, even more in dry soil, and tolerates long periods of summer drought. It is a rhizomatous plant belonging to the agave family, slow-growing in dry soil, faster in moist soil, reaching a height of 2m (6 ft 7 in) outside of flowering. When young, the Dasylirion forms a hairy, very dense ball. After many years, it can form a trunk up to 50cm (19.7 in) in height. This trunk bears a large spherical crown, 1.20m (3 ft 11 in) to 1.80m (5 ft 11 in) wide, composed of several hundred radiating leaves, 60cm (23.6 in) to 90cm (35.4 in) long and 2.5cm (1 in) wide, stiff. They are bordered with white, curved spines, among which are arranged numerous tiny spines. The leaves are leathery, glaucous green, folded at their ends into a kind of small button. Flowering occurs after 10 to 15 years of cultivation, in summer. A slender upright floral spike emerges from the centre of the rosette, among the leaves. The small yellowish flowers are densely packed along the slender spike and remain on the plant for a long time, often until winter. Male plants are distinct from female plants. When watered during the summer, this Dasylirion shows spectacular growth. Careful consideration should be given to the location of this plant and it should no longer be disturbed: its fragile root system does not like to be disturbed at all and does not tolerate transplantation very well.

Dasylirion glaucophyllum requires a lot of sun and very well-drained soil, even poor and dry soil but does not tolerate waterlogged soils in winter. It is perfect on a large dry slope, at the top of a large exotic or contemporary rockery, or even near a swimming pool, if the slightly elevated soil is well prepared to accommodate it. This large plant will simply be magnificent when planted on its own, accompanied by a carpet of cistus, Cerastostigma plumbaginoides, Delosperma, or even a short grass meadow called Zoyzia tenuifolia, the Mascarene grass. It can also be paired with Yucca rigida, Nolina, agaves, prickly pears that are quite hardy (Cleistocactus strausii, Cylindropuntia imbricata), and equally spectacular and frugal shrubby aloes. It is well adapted to container cultivation, which allows it to be protected from cold and humidity in winter.