Pronounciation: Pi-lo-so-SER-e-us leu-co-ce-PHAL-us

Hardiness zones
Sunset 12-24
USDA 9 (with freeze protection)-11

Landscape Use: Strong accent, focal point, xeric and cactus gardens, patio containers, curiosity plant.

Form & Character: Upright, columnar, erect, stout, interesting, blue, xeric.

Growth Habit: Evergreen, succulent, strongly upright, sparsely branched at the base, stems elongated to 25-feet tall, though typically shorter in Phoenix.

Foliage/Texture: Pleated, bluish stems with small white to yellowish-brown areoles on the stem ribs, each areole containing one or two short, stout brownish spines, elongated wooly hairs at the areoles form a graceful cephalium along the stem towards the apex; very coarse texture.

Flowers & Fruits: Large tubular white to pink flowers at the stem apex; fruits rounded, reddish to yellow.

Seasonal Color: None, unless your favorite color is blue.

Temperature: Heat tolerant, but intolerant of freezing winter temperatures.

Light: Partial to full shade, avoid western summer sun and western exposures in Phoenix.

Soil: Well-drained soils are best.

Watering: Irrigated sparingly during spring summer and fall allowing soils to completely dry in between irrigation events, no supplemental water during winter.

Pruning: None

Propagation: Seed, but asexual propagation from callused stem segments is easiest. Cut stems readily regrow.

Disease and Pests: Root rot if soil is wet.

Additional comments: In its native habitat, old man cactus germinates in the shade of plant canopies and in soil-filled rock crevices. Thus in Phoenix landscapes it will need protection from full sun in the form of dappled living or hard shade or full shade from afternoon western sun to avoid stem sunscald injury. Similar to other columnar cacti, old man cactus has a crested form (Pilosocereus leucocephalus forma crestata).

Taxonomic tidbit: The botanical Latin name literally means "hairy candle".