# Old Man Cactus (Cephalocereus senilis)

> Native to Hidalgo and Guanajuato in eastern Mexico, this iconic columnar cactus is renowned for its coat of long, shaggy, silvery-white hairs. This dense woolly fleece serves as an evolutionary adaptation that reflects intense desert sunlight and buffers against extreme temperature shifts. It is a slow-growing species that eventually develops a specialized flowering pseudocephalium in mature wild specimens.

- **Scientific Name:** *Cephalocereus senilis*
- **Botanical Family:** Cactaceae
- **Care Difficulty:** Moderate (2/5)
- **Cold Hardiness:** -2°C (USDA Zone 9b); can survive brief light freezes strictly if the soil is bone dry, though ideal wintering is above 10°C.
- **Pet Safety / Toxicity:** Pet-Safe (Non-toxic to cats and dogs)
- **Canonical URL:** https://sukulentler.com/en/species/cephalocereus-senilis
- **Markdown Source:** https://sukulentler.com/en/species/cephalocereus-senilis.md
- **Botanical Photo:** https://sukulentler.com/assets/images/articles/species_cephalocereus_senilis.webp?v=1794042245

## Light & Sun Exposure

Requires full, direct sunlight for at least 6 hours daily; the density and brilliant white color of its protective hair coat depend heavily on high light and UV exposure.

## Watering Schedule & Method

Extremely susceptible to root rot; apply the soak-and-dry method, allowing the substrate to dry out 100% between waterings. Avoid wetting the woolly hair and keep completely dry in winter.

## Soil & Gritty Mix Formula

70% inorganic grit (pumice, lava rock, coarse perlite, sharp sand) + 30% screened cactus potting soil.

## Cold Tolerance & Overwintering

-2°C (USDA Zone 9b); can survive brief light freezes strictly if the soil is bone dry, though ideal wintering is above 10°C.

## Propagation Methods

Primarily propagated from seed in warm, bright conditions; can occasionally be propagated via stem cuttings or basal offsets if present, allowing wounds to callus thoroughly.

## Available Language Editions

- [TR: İhtiyar Adam Kaktüsü (Cephalocereus senilis)](https://sukulentler.com/tr/turler/cephalocereus-senilis.md)
- [DE: Greisenhaupt (Cephalocereus senilis)](https://sukulentler.com/de/arten/cephalocereus-senilis.md)
- [ES: Cabeza de Viejo (Cephalocereus senilis)](https://sukulentler.com/es/especies/cephalocereus-senilis.md)