Hardiness zones:
Sunset 10-24
USDA 9-11 (arid regions best)
Landscape Use: Xeric accent shrub, strong attractant of hummingbirds which are very territorial about this plant, also attracts bees.
Form & Character: Evergreen shrub, open stiff to graceful, INFORMAL (don't shear), C. californica is typically more luxuriant and vigorously upright than C. eriophylla though hybridization and the resultant genetic mixing of these two landscape plant taxa within the Phoenix urban environment has muddled this.
Growth Habit: One form is upright from base to 4-8' while another form is coarse branching and spreading to only 2' to 3' in height.
Foliage/texture: Small pinnately-compound leaves, leaves close during night; fine texture.
Flowers & fruits: Numerous brilliant red pin cushion flowers in terminal and auxiliary clusters followed by erect to upright pubescent pods to 3" long
Seasonal color: Sometimes spectacular displays of red flowers during the entire year except summer, most prevalent in November to March.
Temperature: Highly tolerant of lower desert heat and is cold tolerant to 22oF.
Light: Full sun (no shade)
Soil: Red fairy duster is tolerant of all lower desert Arizona soils, though well-drained drier soils are best. Foliar chlorosis or leaf yellowing can develop if soils are chronically wet.
Watering: Apply infrequent and deep supplemental watering during extended dry periods only for best appearance. Irrigations will also increase overall plant vigor and eventual size. Do not excessively water as this will promote rank vegetative growth and a reduced flower display. Both red (California) and Baja fairy duster shrubs are prone to lose leaves (drought deciduous habit) during extended periods of dry soil conditions - don't freak out, this is okay.
Pruning: Don't regularly shear or hedge this beautiful desert shrub. Rather head back lightly to severely individual stems and branches to different lengths as necessary in early summer to promote a full canopy of foliage.
Propagation: Acid scarification of seed in order to seed propagate, otherwise vegetative cutting (use a perlite based medium) is more difficult.
Disease and pests: None
Additional comments: Red fairy duster is a tremendous addition to
any xeric landscape design. Calliandra californica and eriophylla
will readily hybridize. This makes urban seed collection interesting
because progeny (seed produced offspring) are just as likely to have a mixed up
array of pink and/or red flower colors and a range of growth habits from
prostrate to stiffly upright. Naturalization (reseeding) of
Calliandra species in the Phoenix urban environment is common and is
stimulated around points of irrigation or in areas mulched with gravel (enhanced seed scarification).
'Sarita' is a cultivar of C. californica with a profoundly low, prostrate habit that was found and patented by Sarah Celestian, a former
graduate student of mine while she was working at Desert Tree Farm in Phoenix, Arizona.
