Peruvian old man cactus
Give it the sunniest spot you have and be strict about the dry winter rest from the first year — this is a plant where doing less is doing better.
Care
Full sun — the brightest windowsill in the house, all year.
Very low — water thoroughly but rarely in summer, letting the compost dry right out; keep it completely dry through the winter rest.
Gritty, very free-draining cactus compost, ideally with extra perlite or coarse sand. A plastic pot holding damp compost is the classic way to lose one.
None. Don't remove the white woolly hairs, which are the plant's sun protection, and handle it as little as possible — the wool hides fine spines.
A high-potash cactus feed once a month during the summer growing season only. Nothing at all from autumn through winter — the dry, cool, unfed rest is what keeps the column growing evenly rather than soft and bulging.
Offsets are rare on a young plant; when one appears, cut it off cleanly, let the wound callus for at least a week, then set it on dry gritty compost and leave it unwatered for another week. Seed is the commercial route and is very slow.
Month by month
Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.
- AprilStart watering again, sparingly, as the light improves and growth restarts. how ›
- JuneFeed monthly with a cactus fertiliser through the summer. how ›
- OctoberStop watering completely for the winter rest. how ›
- NovemberKeep it cool, bright and bone dry over winter — cold and damp together is what kills a cactus. how ›
Months based on climate: UK. Your choice stays on this device.
- AprilStart watering again, sparingly, as the light improves and growth restarts. how ›
- JuneFeed monthly with a cactus fertiliser through the summer. how ›
- OctoberStop watering completely for the winter rest. how ›
- NovemberKeep it cool, bright and bone dry over winter — cold and damp together is what kills a cactus. how ›
Months based on climate: Northern Italy. Your choice stays on this device.
- MarchStart watering again, sparingly, as the light improves and growth restarts. how ›
- JuneFeed monthly with a cactus fertiliser through the summer. how ›
- OctoberStop watering completely for the winter rest. how ›
- NovemberKeep it cool, bright and bone dry over winter — cold and damp together is what kills a cactus. how ›
Months based on climate: Central Italy. Your choice stays on this device.
- MarchStart watering again, sparingly, as the light improves and growth restarts. how ›
- JuneFeed monthly with a cactus fertiliser through the summer. how ›
- NovemberStop watering completely for the winter rest. how ›
- NovemberKeep it cool, bright and bone dry over winter — cold and damp together is what kills a cactus. how ›
Months based on climate: Southern Italy and islands. Your choice stays on this device.
Common problems
How to spot it. The base goes brown and soft, usually after winter watering.
What to do. Keep it dry from autumn to spring; cut above the rot and re-root the healthy top if the plant is worth saving.
How to spot it. A narrow, pale, stretched section at the top of the column.
What to do. Too little light — move it to the brightest position available; the stretched part will not thicken again.
How to spot it. White cottony patches hidden in the wool, hard to spot.
What to do. Inspect regularly and remove with a cotton bud; the plant's own wool makes this pest easy to miss.
Questions
Peruvian old man cactus: is it hardy?
H2: Tender. It survives down to 1 °C.
Can it grow in a pot?
Yes — a terracotta pot barely larger than the plant, which dries out fast and suits it perfectly.
Peruvian old man cactus: when do you prune it?
None.
When do you feed it?
A high-potash cactus feed once a month during the summer growing season only. Nothing at all from autumn through winter — the dry, cool, unfed rest is what keeps the column growing evenly rather than soft and bulging. Feeding months, UK: May–July.