July 23, 2015
Beautiful Yucca rostrata is one of the tree-form species, with long, slender blue-gray leaves that are truly stunning garden architecture.
This “tree” will reach its ultimate height of 8 to 10 feet tall in about a decade, making it fairly fast-growing.
Unlike some desert species, Yucca rostrata is extremely winter hardy, listed to USDA Zone 5, or -15 degrees F.
Plant in full sun in very well-drained soil. In fact, if you have heavy clay soil, this desert species should be avoided, as it has zero tolerance for wet feet. But if you have areas that you can convert to rock gardens and increase the drainage with decomposed granite or other small aggregate rocky substrate, this plant will be very happy with minimal care.
Water very little during establishment, then not at all once established. When it flowers in late spring to summer, a small bloom stalk will begin to emerge from the center of tree and will very quickly grow several feet, opening to a towering inflorescence of gorgeous white/pale yellow, bell-shaped flowers.
Unlike many desert species, Yucca rostrata isn’t terribly pointy, but the thin, linear leaves are very fibrous and thick, and give a mean cut if not handled properly. Older foliage will die back, creating a “skirt” of dead leaves around the trunk, just below the living foliage. Some people want to remove that foliage, but resist the urge. It’s a lot of work, and the plant actually looks more attractive and natural with it there.
Yucca rostrata is evergreen and will provide structural interest in the garden all year long. It looks most striking when planted in a grouping of several, with very little else around at eye level. Consider planting some lower-growing desert species in the same bed, but leave the space at eye level free for Big Bend Yucca’s full effect.