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Cactus Old Man

Cephalocereus senilis

houseplant

verifiedReviewed by the GreenScout Team

Old Man Cactus is a distinctive columnar cactus named for its long, hair-like spines that resemble grey hair, creating a dramatic and otherworldly appearance. Native to Mexico, it grows slowly and can eventually reach 30 feet in nature but remains compact indoors for many years. It produces white flowers at night and requires excellent drainage and bright light.

Common Problems

Select the problem your Cactus Old Man is experiencing to get a treatment guide.

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Overwateringchevron_right

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Root Rotchevron_right

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Mushy Stemschevron_right

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Slow Growthchevron_right

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Pale Leaveschevron_right

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Wiltingchevron_right

Care Guide

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Light

Bright, direct sunlight for 6+ hours daily; insufficient light causes sparse hair-like spines and weak growth.

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Water

Water sparingly during growing season; allow soil to dry completely between waterings. Minimal water in winter.

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Soil

Fast-draining cactus or succulent mix with added perlite or grit for excellent drainage.

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Fertiliser

Diluted succulent fertilizer once in spring and once in early summer; avoid over-fertilizing.

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Temperature

Prefers 50–85°F (10–29°C); tolerates occasional dips to 40°F (4°C); protect from freezing temperatures.

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Humidity

Very low humidity essential; moisture promotes rot and fungal issues.

Toxicity

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Non-toxic but spines are sharp; position carefully to avoid accidental injury.

Common Diseases

filter_dramaRoot Rotchevron_right scienceSooty Mouldchevron_right

Common Pests

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Seasonal Care

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Resume regular watering and feeding as growth picks up.

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Peak growing season. Water and feed regularly.

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Reduce watering as growth slows. Stop heavy feeding.

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Minimal watering and feeding. Protect from frost if needed.

Frequently Asked Questions

Why is my Cactus Old Man losing its characteristic "hair"?

The long white hairs are modified spines, and some shedding of the oldest hair near the base is normal as the plant grows taller. Consistent bright light helps keep the hair dense along the whole column.

Is the fuzzy hair on Cactus Old Man safe to touch?

Be careful — underneath the soft-looking hair are sharp spines, so what looks cuddly can still prick. Handle it the same way you would any spined cactus.