Scientific: Opuntia santa-rita (There is much taxonomic confusion about the name. Other recognized scientific names include but are not limited too: Opuntia santa rita var. violacea, Opuntia macrocentra var. macrocentra, Opuntia violacea var. macrocentra, Opuntia gosseliniana, 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 desert style gardens, container plant.

Form & Character: Shrubby cactus, rigid, dry, colorful.

Growth Habit: 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 blades or pads which store water.

Blue blade pads are generally glaucous blue. Immature blue blade pads or pads that are cold or drought stressed will have a distinct purple tinge. All blue blade pads are orbicular (rounded to circular) to 8 inches long and wide. Mature pads are leafless whereas emerging juvenile pads in spring have many small cylindrical leaves that each taper to a point. Mature pads 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 pad aeroles are whitish brown with very short, but very potentially aggravating, glochids; coarse texture.

Flowers & fruits: Flowers cream to yellow on ends of highest pads, reddish fruit in late summer and fall.

Seasonal color: Consistently blooms in April to May.

Temperature: Hardy to 25oF.

Light: Full sun to partial shade.

Soil: Tolerant

Watering: Extremely drought tolerant, but an occasional summer soaking will keep pads flush.

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 Phoeinix 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.

RECOMMENDATION: If you're is not prepared to take frequent and regular preventative measures to prevent or minimize this pesky scale insect, then my recommendation is to NOT plant this otherwise wonderful cactus in your yard.

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.