Accent · Sonoran native
Spanish Dagger (Mojave Yucca)
Yucca schidigera · Asparagaceae (Agavoideae)
Also called: Mojave Yucca, Mohave Yucca, Spanish Dagger
Spanish Dagger (Mojave Yucca) (Yucca schidigera) is a very low-water accent native to the Sonoran Desert region well suited to Tucson and the low desert.
Spanish Dagger (Mojave Yucca) at a glance
- Water use
- Very Low (established)
- Sun
- Full sun with reflected heat; tolerates intense low-desert sun. Not for shade or humid sites.
- Mature size
- Typically 6-12 ft H (old plants to ~16-20 ft) x 4-8 ft W; develops one or several thick trunks topped with dense bayonet-leaf crowns.
- Growth rate
- Slow; long-lived.
- Bloom
- Creamy white, often purple- or pink-tinged, in a dense club-shaped cluster partly nested in the leaves., Spring, roughly April-May.
- Cold hardiness
- Hardy to roughly 10°F (some sources 0°F); USDA zones 8-10. Well suited to Tucson winters; dislikes excess rainfall/humidity.
- Soil
- Sharp-draining sandy, gravelly, or rocky desert soils; tolerant of caliche and alkalinity. Excellent drainage essential.
- Native range
- Native to the Mojave Desert, Sonoran Desert (including western/southwestern Arizona), and southern California/Baja California; native to Arizona, primarily its western reaches.
- Best used as
- Bold architectural specimen/accent, Vertical silhouette and barrier/security planting (sharp leaves), Native and desert revegetation, Xeriscape focal point, Reflected-heat exposures
- Wildlife
- Pollinated by its specific yucca moth; flowers and fruit eaten by wildlife. A major commercial source of steroidal saponins (used in animal feed, foaming agents); fibers used for cordage. Sharp leaves deter browsing.
- Toxicity
- Contains steroidal saponins; ingestion can cause vomiting/diarrhea in pets and people, and the stiff, sharp 'dagger' leaf tips are a significant puncture hazard. Site well away from walkways, play areas, and pets.
How to grow Spanish Dagger (Mojave Yucca) in Tucson & the low desert
Watering
Very drought tolerant once established; deep soak only every 3-4 weeks in summer heat and little to none otherwise. Overwatering and poor drainage cause rot; keep dry in winter.
Fertilizer & nutrients
Not required in desert soils. Mature plants need no feeding; a single light spring application of slow-release fertilizer may aid establishment of young plants only.
Pruning & care
Minimal. Remove spent flower stalks and groom dead lower leaves to reveal the trunk if a clean look is wanted. Leaves are extremely rigid and needle-tipped, so prune with thick gloves and eye protection.
Notes
The stoutest, most rigid-leaved of this group: thick, yellow-green, sword-shaped leaves with fine curling marginal fibers on a substantial trunk. 'Spanish dagger' refers to the formidably sharp leaf tips. Slow-growing and long-lived; buy at desired size and place where the spines won't be a hazard.
Sources: AMWUA / Water Use It Wisely desert plant references; Arizona-Sonora Desert Museum 'Genus Yucca'; University of Arizona Cooperative Extension; Jepson/SEINet floras for native range; peer-reviewed literature on Yucca schidigera saponins