Cephalocereus senilis

Old Man Cactus

◆

Taxonomy

Common Names

Old Man Cactus

Context

nativeRegion

Eastern Mexico (Hidalgo and Veracruz states)

usdaZones

9-11

companionPlants

Other columnar cacti, Agave spp., Echinocactus grusonii, Opuntia spp.

culturalUses

Popular as an ornamental cactus for its distinct white hair; occasionally used in xeriscaping.

Care

LightFull sun is ideal; requires bright, direct sunlight for healthy growth.

WateringWater sparingly, allowing soil to dry completely between waterings. Overwatering can cause root rot.

SoilWell-draining cactus or succulent potting mix with added sand or perlite.

FertilizerFertilize lightly with a cactus fertilizer during the growing season (spring-summer), once a month.

HumidityPrefers low humidity; high humidity can lead to fungal problems.

TemperatureEnjoys warm temperatures; keep above 10°C (50°F). Not frost-tolerant.

HabitColumnar cactus with densely hairy, white 'old man' fuzz covering the stem.

Mature SizeUp to 12 meters tall (40 feet) in nature; typically 1-2 meters in cultivation.

Growth RateVery slow-growing.

BloomingRarely blooms in cultivation; mature plants (decades old) may produce nocturnal pinkish-red flowers.

DormancyDormant in winter; reduce or stop watering during this period.

MethodsSeed, Cuttings (less common)

DifficultyModerate

Best SeasonSpring

PruningNo regular pruning needed. Remove damaged or rotting stems if necessary.

RepottingRepot every 2-3 years or when rootbound, preferably in spring.

Pests & DiseasesWatch for mealybugs, scale, and root rot from overwatering.

ToxicityNon-toxic to humans and pets.

No public plants yet.