Accent
Beaked Yucca
Yucca rostrata · Asparagaceae (Agavoideae)
Also called: Big Bend Yucca, Blue Beaked Yucca
Beaked Yucca (Yucca rostrata) is a very low-water accent well suited to Tucson and the low desert.
Beaked Yucca at a glance
- Water use
- Very Low (established)
- Sun
- Full sun with reflected heat; tolerates light shade but stays densest and bluest in full sun.
- Mature size
- Typically 6-12 ft H (to ~15 ft with age) x 3-6 ft W; a single (occasionally branching) trunk topped by a spherical head of fine blue leaves.
- Growth rate
- Slow to moderate.
- Bloom
- Creamy white flowers in a large showy panicle held well above the foliage., Late spring to early summer (roughly April-June) on mature plants.
- Cold hardiness
- Exceptionally cold hardy, to about -10°F to -20°F (USDA zones 5-10); one of the hardiest trunk-forming yuccas and fully hardy in Tucson.
- Soil
- Sharply drained sandy, gravelly, or rocky soils; tolerates caliche and alkalinity. Good drainage is essential to prevent crown rot.
- Native range
- Native to the Chihuahuan Desert of west Texas (Big Bend region) and northern Mexico (Chihuahua, Coahuila); not native to Arizona/Sonoran Desert but an outstanding, well-adapted ornamental for the Tucson low desert.
- Best used as
- High-end sculptural specimen/focal point, Modern and xeric garden designs, Containers and entry/courtyard accents, Vertical structure in low-water plantings, Reflected-heat and slope plantings
- Wildlife
- Flowers attract native pollinators and are visited by yucca moths; provides some nectar and seed. Generally rabbit- and javelina-resistant.
- Toxicity
- Low toxicity; like other yuccas contains saponins that can cause mild GI upset if ingested. Leaf tips are pointed but less hazardous than the dagger yuccas. Generally considered safe for ornamental use.
How to grow Beaked Yucca in Tucson & the low desert
Watering
Very drought tolerant once established; deep watering every 3-4 weeks in summer is ample and little to no water is needed in cooler months. Avoid frequent shallow irrigation and standing water, which cause rot.
Fertilizer & nutrients
Not required in desert soils. Optional single light spring application of slow-release fertilizer can modestly speed growth on young plants; mature plants need none.
Pruning & care
Low maintenance. Remove spent bloom stalks; the fine dead leaves form a tan 'skirt' that can be left for a natural look or trimmed to expose the trunk. Do not cut the crown. Leaf tips are stiff but only moderately sharp.
Notes
Prized for its symmetrical perfectly spherical head of very fine, thin, powder-blue leaves (the 'beaked' refers to the small beak on the seed capsule) atop a slender trunk that develops an attractive thatch. The most refined and 'designer' yucca in this set; selections such as 'Sapphire Skies' have especially blue foliage. Buy at size as it grows slowly.
Sources: AMWUA / Water Use It Wisely desert plant references; Arizona-Sonora Desert Museum and University of Arizona Cooperative Extension landscape guides; Tohono Chul / Tucson Botanical Gardens plant collections; Horticulture nursery references (Monrovia, regional desert nurseries) for cold-hardiness and origin