Scientific: Yucca aloifolia
Common: Spanish bayonet
Family: Asparagaceae (subfamily Agavoideae)
Origin: Southern United States, West Indies, Mexico
Pronounciation: YUK-ka a-lo-i-FOL-ee-a
Landscape Use: Background, textural accent, container plant, Spanish or Mediterranean architecture.
Form & Character: Clean, but foreboding, clumping, very stiff, upright, rigid, not people friendly.
Growth Habit: Evergreen, perennial, semi-woody, slowly and stiffly upright, single trunk to clumping to 25 feet, but can be maintained at much lower height and is generally much smaller in Phoenix.
Foliage/Texture: Strap leaves to 2 1/2 feet long, rigid, very sharp pointed and DANGEROUS! Closely set on stems, margins denticulate but not thread bearing; medium coarse texture.
Flowers & Fruits: Extended panicles to 2 feet of cream white flowers, sometimes tinged with purple to 4 inches across, fruit are not that cool looking.
Seasonal Color: Crem white flowers on tall stalks during late April through mid June.
Temperature: Heat tolerant, cold hardy to 10oF.
Light: In Phoenix, shade from western sun is preferred.
Watering: Spanish bayonet is more drought tolerant that Y. gloriosa or Y. recurvifolia, but will still need regular supplemental water especially during summer months.
Pruning: Remove old flower stalks.
Propagation: Seed, cuttings (very easy to root), division.
Disease and Pests: Spider mites
Additional comments: Spanish bayonet is a stately yucca for those Mediterannean or Spanish type landscape designs. It is quite dangerous due to its stiff and pointed foliage and as such must not be planted in close proximity to human foot traffic (walkways, paths, patios, etc.). There are several variegated cultivars that are not commonly seen in Phoenix. In general, Spanish bayonet is somewhat more tolerant of full sun in Phoenix than Spanish dagger, but neither are desert plants.