Puya castellanosii

The Puya castellanosii is part of this group of succulent perennial plants related to pineapples that grow in the arid heathlands of the Andes Mountains. This one, rare in cultivation, is a very beautiful species native to northern Argentina that is interesting for its resistance to dry cold, quite easy to acclimate to the sun in many gardens that are not too humid and not too cold in winter. It forms dense rosettes of spiny gray-blue-silver leaves, very bright, and produces tall flower spikes, rose-violet in color, loaded with pastel blue flowers. In mild climates, it is an excellent rock garden or dry garden plant, without watering. Elsewhere, it can easily be grown in a pot to protect it from cold and damp in winter.

The Puya castellanosii is a perennial plant from the bromeliad family. It is native to the Andes in northern Argentina in the Salta Province, where it develops in large colonies on dry slopes and mountainsides, between 2300 and 3500 meters (7546 and 11483 feet) above sea level. In its natural habitat, it is one of the dominant species in these rocky and arid lands and in these wind-swept meadows where only grasses and dwarf bushes survive. It is a plant that requires dry and well-draining, sandy, poor and limestone soil. Very well adapted to the harsh climate that characterizes its native lands, the Puya castellanosii also endures high solar radiation, snow, very high temperatures during the day, and very low temperatures at night. It can withstand frosts of around -10°C (14°F) in well-drained soil.

The Puya castellanosii grows slowly. It reaches a height of 1 meter (3 feet) and spreads over time to form large clumps of 3 meters (10 feet) in diameter composed of multiple rosettes. The plant forms rosettes of very long leaves covered with a silver-colored wax and bordered by inward-curving spines, brown in color. Mature rosettes, several years old, bloom in late spring. From the center of the rosette emerges a flower spike that can rise up to 1.50 meters (5 feet), or even 2 meters (7 feet), from the ground. This branched inflorescence bears numerous pale blue tubular flowers enclosed in rose-violet bracts and covered with a fine silver fuzz.

The Puya castellanosii requires to be planted in perfectly draining, limestone, and dry soil in winter. This collector's plant finds its place in a rock garden or a gravel garden in a climate that is not too cold and rather dry. It should thrive in our Mediterranean regions or in the southwest. To accompany it in an arid-style rock garden or on a contemporary terrace, consider, for example, Yuccas, Dasylirions, Phormiums, and Nolinas. This plant is easily grown in a pot, in a cactus-type substrate. As soon as the first cold weather arrives, you should store it away from humidity and cold, handling it with caution due to its spines, in a greenhouse or conservatory.