Scientific: Opuntia santa-rita
Taxonomic note: There is much taxonomic confusion about the correct scientific name. Other recognized scientific names or synonyms include but are not limited too: Opuntia santa rita var. violacea, Opuntia macrocentra var. macrocentra, Opuntia violacea var. macrocentra, Opuntia gosseliniana, and Opuntia violacea var. castetteri
Common: Santa rita prickly pear cactus, blue blade, dollar cactus, purple prickly pear
Family: Cactaceae
Origin: Texas, New Mexico, and Arizona south into northern Mexico.
Pronounciation: O-PUN-tee-a SAN-ta REE-ta
Hardiness zones:
Sunset 13, 18-24
USDA 9-11
Landscape Use: Stem and flower accent cactus for xeric and desert style landscapes, barrier planting in desert gardens, large patio containers.
Form & Character: Shrubby rounded cactus, rigid, dry, very colorful.
Growth Habit: Evergreen, perennial succulent, moderate growth rate, upright and many branched to 6 feet in height with equal spread.
Foliage/Texture: Stems of Opuntia are jointed into flattened sections called clades, blades or pads which store water. Blue blade clades are generally glaucous blue. Immature blue blade clades that are cold or drought stressed will have a distinct purple tinge. All blue blade clades are orbicular (rounded to circular) to 8-inches long and wide. Mature clades are leafless whereas emerging juvenile clades in spring have many small, cylindrical leaves that each taper to a point. Mature clades are also generally spineless, though occasionally a terminal pad will have infrequent clusters of spines to 2-inches long mostly on upper margins, spines tinged reddish-brown to pink. Instead of spines, all blue blade clade aeroles are whitish brown with very short, but very potentially aggravating, glochids; coarse texture.
Flowers & Fruits: Flowers cream to yellow on ends of highest clades; fruits reddish orbs in late summer and fall.
Seasonal Color: Consistently blooms in April to May.
Temperature: Heat tolerant, cold hardy to 25oF.
Light: Full sun to partial shade.
Soil: Tolerant
Watering: Extremely drought tolerant, but an occasional summer soaking will keep pads flush. If water stressed, pads will become reddened.
Pruning: None
Propagation: As with all Opuntia, blue blade cactus easily roots at the basal end of pads, seed (generally unnecessary).
Disease and Pests: Mealy bugs (infrequent problem in outdoor landscapes) is minor.....but cochineal scale is a HUGE problem in outdoor Phoenix landscape gardens. This pesky sucking insect attaches itself onto the clades at frequencies that will astonish you. It looks
like cottony cushion scale and produces a purplish red dye. Cochineal scale on blue blade cactus is way difficult to control. In my yard, I try to "prevent" infestations by reducing stem pad density (removing pads in July) to avoid crowding and allow good air flow, and by periodically spraying off the cactus clades (stem pads) with a garden hose fit with a high pressure nozzle.
Additional comments: One of many good species of Opuntia for use
in Phoenix. Since the botanical name of this cactus has changed several times in the last
20 years, don't be surprised at others you may meet who hold fast to calling it by an older scientific name.
Final recommendation: If you're not prepared to take frequent actions to prevent or minimize the damage caused by the pesky cochineal scale insect, then my recommendation is to NOT plant this otherwise wonderful cactus in your yard.
