Scientific: Hesperaloe parviflora
Common: red hesperaloe
Family: Asparagaceae (subfamily Agavoideae)
Origin: Chihuahuan desert from New Mexico and Texas south into old Mexico.
Pronounciation: Hes-per-AL-oo par-vi-FLOR-a
Hardiness zones
Sunset 10-16, 18-21
USDA 8-10 (arid and semi-arid regions)
Landscape Use: Floral and textural accent, oasis, xeric and desert landscape designs, container plant. Interesting when massed into groups; strongly attracts hummingbirds (image captured in my backyard by famous Bulgarian artist and photographer, Hari Ivanov Atanasov).
Form & Character: Basally clumping, upright, agave like, stiff, dry and xeric, informal, unconfined.
Growth Habit: Red yucca is an evergreen, acaulescent, herbaceous perennial shrub. It is generally a slow grower, basally clumping to 2- to 4-feet tall (there is genotypic variation that expresses as larger or smaller), but with flower stalks that extend up to 8- to 10-feet tall. Water availability will have a profound effect on its eventual size.
Foliage/Texture: Red yucca leaves are gray green, curved, strap-like leaves to 30-inches long with numerous white filament hairs on margins; medium fine texture.
Flowers & Fruits: True to its common name, red yucca produces numerous long and extended flower stalks with numerous flowers with salmon pink petals and yellow styles. Fruit are a green to brown (when mature) multiple carpulate capsule, somewhat ugly.
Seasonal Color: Festive display of flowers during spring. The young flower stalks are almost as colorful and attractive as the flowers themselves.
Temperature: Red yucca is highly adapted to southwest desert conditions.
Light: Full sun
Soil: Grows best in gravelly, well-drained soil.
Watering: Drought tolerant, infrequent summer irrigations (it's a Chihuahuan Desert native after all). More robust and faster growth will occur with more water; thus, control supplemental watering to regulate red yucca size and vigor.
Pruning: Remove old flower stalks during summer. Shearing red yucca by giving it a 1950's era 'spike' hair style is terribly bad form. Sadly, this abusive practice is wielded upon red yucca shrubs regularly throughout the Phoenix area by the ignoble 'Horticultural clods of Phoenix' (aka 'Hort clods') that call themselves 'landscape professionals'. Those that do this abusive practice to red yucca are manifesting their horticultural illiteracy.
Propagation: Seed, division of clumps of mature specimens.
Disease and Pests: Fungal root rots in damp, heavy soils, aphids on emerging flower stalks during early spring.
Additional comments: Red yucca is currently a landscape staple in Phoenix and is now found in southern California and Texas landscapes as well. It is an excellent "smaller" arid shrub that is well suited for today's smaller, drier urban spaces. 'Yellow' is one (albiet uncreative) name for the yellow flowering variant of this species. Though novel, in my humble opinion the yellow flower color is not as attractive as the red flowering phenotypes. There are several new and exciting red cultivars including 'Sandia Glow', 'Desert Dusk', and 'Desert Flamenco'. One amazing red flowering cultivar is 'Brakelights' P.P.A.F. This patented cultivar from Mountain States Wholesale Nursery in Glendale, AZ, is a compact little plant to about 2-feet tall and wide and can bloom for up to 9 months during the year in Phoenix with traffic stopping red flower spikes. Whoa doggie!!! Its only real draw back is that aphids (farmed by ants) love the floral juices and form dense colonies on the juicy succulent young flower stalks during spring.
Hesperaloe parviflora can hybridize with Hesperaloe funifera. Here is Hesperaloe x 'Pink Parade', a parviflora x funifera hybrid with beautiful pink flowers that is also from Mountain States Wholesale Nursery, Glendale, AZ.
Derivational tidbit: 'Hespero' is latin for 'western'; thus Hesperaloe literally translates western aloe.