Yucca Rigida is also called Mexican Blue Yucca, Silver Leaf Yucca, or Palmilla and is part of the Agavaceae. This bush originates from Mexico (Chihuahuas desert). The name "rigida" just means "rigid" in Latin. The blue tinge of its foliage and its striking appearance make it a very desirable specimen in a garden. This Yucca is arborescent with 1 to 3 stems up to 450 cm (15 ft) tall and 12 to 15 cm thick, and about 1.8 m (6 feet) spread, none or few branches rosettes with many leaves.
The long flat powder blue-gray leaves, tipped with a spine, adorn this 12' tall upright grower. The leaves of Y. rigida are generally wider, less twisted, and less flexible than Yucca rostrata. The leaves are linear, slightly wider at the middle and canaliculated, about 3 feet long by about 1 1/4 inches wide. As the lower leaves of the Yucca Rigida mature, they turn brown and fall down parallel to the trunk and become attached to the trunk by a glue-like material that is found underneath each leaf.
The Yucca rigida inflorescence is pubescent, and the flowers (3-6 cm) are creamy white and bell shaped. They are borne on a 2 ft spike and are held slightly down in the foliage. Y. rigida is a stunning specimen plant for the dry garden. This plant blooms in late spring on a 5 to 6 foot stalk. The pretty white flowers in late spring are followed by woody capsules. The fruits are 3,5 to 7 cm long, 1,8 to 2,5 cm thick and the seeds are black, dull, with small wings.
Hardiness zones: 7-10 (-15°C/ 5°F, 1°C/35°F) in winter. This Yucca is hardy to 10°F (-12°C). This tree needs moderate water and well drained soil. It will grow well in full sun but tolerates light shade. This yucca has excellent heat and drought tolerance.