Espostoa melanostele – Peruvian Old Man Cactus

Columnar, woolly, and deceptively spiky, Espostoa melanostele combines softness and strength. Beneath its white fuzz lie clusters of dark spines, evolved to protect the plant from harsh sun and grazing animals in its Andean homeland. A stunning vertical grower that may develop a cephalium in maturity, it thrives in bright, dry conditions.

Scientific Name
Espostoa melanostele (melanostele = “black column”)

Synonyms
Sometimes sold as Pseudoespostoa melanostele in cultivation

Common Name
Peruvian Old Man Cactus, Cotton Pole Cactus

Origin
Andes of Peru – arid, high-elevation slopes

Light
Bright light with several hours of direct sun daily. Ideal on a south- or west-facing windowsill. Supplement with grow lights in darker months.

Water
Water when soil is fully dry – usually every 2–3 weeks in summer. Water sparingly in winter. Always water at soil level; avoid wetting the fuzz.

Humidity
Low humidity preferred. Needs good airflow. Avoid damp or steamy rooms.

Soil
Use a very free-draining cactus mix with added grit or perlite. Ensure pot has drainage holes.

Food
Feed every 4–6 weeks during spring and summer with a cactus feed. No feeding in winter.

Temperature
Prefers 20–28°C. Can tolerate down to 5°C if dry. Keep frost-free.

Pet-safe
No – spiny and mildly toxic if ingested.

Sprouts Top Tips
That soft-looking fuzz hides sharp spines! Always handle with gloves.

Extras
May form a cephalium – a dense woolly flowering area – on mature plants.

Did You Know?
The fuzzy outer layer helps reflect sunlight and trap a layer of still air, reducing moisture loss in the harsh mountain sun.