Peruvian Old Lady Cactus
espostoa melanostele
Also known as: ["Peruvian Old Lady","Old Lady Cactus"]
Overview
A columnar cactus native to Peru, covered in dense white spines and wool, known for its nocturnal flowers.
Benefits & Perks
["drought tolerant","rare/collector’s item","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Caryophyllales |
| Family: | Cactaceae |
| Genus: | Espostoa |
| Botanical Name: | Espostoa melanostele |
Plant Characteristics
Basic Information
- Category: Succulents & Cacti
- Suitable Location: indoor pot in bright, sunny location or outdoor in well-drained, sunny garden bed
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"5–30°C"}
- Hardiness: {"zones":"9–11"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent waterlogging.
- Soil Type: Well-draining cactus or succulent mix with added perlite or coarse sand for aeration.
Maintenance Level
- Maintenance Level: low
- Toughness Level: high
- Pruning Frequency: As needed, typically annually or when offsets become crowded.
- Pruning Intensity: Light to moderate; remove only dead or unwanted growth.
Care Details
Ideal Sunlight Coverage:
Bright indirect light or several hours of direct morning sun (4–6 hours); adjust to avoid intense afternoon sun, especially in summer.
Sunlight Tolerance Tips:
Acclimate gradually to direct sun to prevent sunburn; provide shade during peak summer heat; indoors, place near a south-facing window with filtered light.
Care Requirements
Care Difficulty
moderateEasy
Sunlight
full sun to partial shade
Rotate plant weekly for even growth; avoid sudden light changes; use sheer curtains to diffuse intense sun.
Watering
every 7–10 days during growing season, every 3–4 weeks in winter
Water deeply but infrequently; ensure soil dries fully between waterings; reduce water significantly in winter.
Soil
fast-draining cactus mix with coarse sand or perlite
pH: Slightly acidic to neutral (pH 6.0–7.0).
Use gritty soil mix; ensure pots have drainage holes; avoid heavy, water-retentive soils.
Temperature
Prefers warm temperatures (65–85°F or 18–29°C); tolerates mild frost but thrives in warmth; reduce water in cooler temperatures.
Protect from frost; ensure good air flow in heat; adjust watering with temperature changes.
Fertilizing
every 4–6 weeks during active growth with diluted cactus fertilizer
Fertilize only when actively growing; flush soil occasionally to prevent salt buildup; stop fertilizing in winter.
Propagation
Methods
Stem cuttings or offsets (pups); cuttings root easily when taken from healthy, mature stems.
Step-by-Step Propagation Guide
- Cut a healthy stem or offset.
- Let the cut end callous for a few days.
- Plant in dry soil.
- Water lightly after roots form.
Best Time: Spring or early summer when the plant is actively growing.
Environment
Warm, humid environment with indirect light; maintain moderate humidity around the cutting.
Medium
Well-draining mix of cactus soil and perlite or sand; can also root in water for a short period.
Hormone
Rooting hormone is optional but can speed up rooting.
Timeline
Roots may form in 2–4 weeks; establish in new pot within 2–3 months.
Tools Needed
Sharp, sterile knife or scissors, rooting hormone (optional), small pots, well-draining soil.
Quick Tips
Allow cut end to callous before planting; use a small pot to limit soil volume; avoid overwatering until roots develop.
Pruning & Repotting
Pruning Guide
Method
Cut stems cleanly with a sharp tool; allow cuts to callous before handling or repotting.
Pruning Plan
Minimal pruning needed; focus on removing offsets for propagation or removing damaged/dead segments.
Tools
Sterile knife or pruning shears, gloves.
Checklist
Sterilize tools; cut cleanly; allow callousing; dispose of pruned material properly.
Repotting Guide
Best Season
Spring, when the plant is entering its active growth phase.
Pot Size
Move to a pot one size larger (1–2 inches in diameter increase); ensure good drainage holes.
Method
Remove the plant carefully; trim any dead roots; repot in fresh, well-draining soil; avoid watering for a week to prevent rot.
Suggestions
Repot every 2–3 years or when the plant outgrows its container; offsets may be separated during repotting.
Checklist
Check root health; use fresh soil; ensure proper drainage; avoid immediate watering.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil dryness; water deeply; ensure drainage; reduce winter watering.
How to Apply Water Properly
Water directly at the root zone until water drains from the bottom; ensure even moisture without waterlogging; water in the morning to allow foliage to dry.
Watering Schedule Tips
Water thoroughly during the growing season (spring and summer) every 7–10 days, allowing the soil to dry completely between waterings. Reduce watering to once a month or less in fall and winter, ensuring the soil remains dry for extended periods.
Soil Improvement
Add coarse sand, perlite, or pumice to commercial potting soil to enhance drainage and aeration.
Temperature Stress Management
Signs of Temperature Issues
Chlorosis or purpling of stems in cold; sunburn or bleaching in excessive heat; stunted growth in temperature extremes.
Cold Stress
Low temperatures slow growth and increase susceptibility to root rot due to reduced water uptake and metabolic activity.
Solution: Move to a warmer location; insulate the pot; reduce watering; avoid fertilizing in cold conditions.
Hot Stress
Excessive heat can cause dehydration, sunburn, or scorching of the cactus skin, leading to tissue damage.
Solution: Provide shade during peak heat; increase air circulation; water carefully to avoid overheating the roots.
Fertilizing Guide
Fertilizing Checklist
Use diluted fertilizer; apply during growing season; avoid winter feeding.
Fertilizing Method
Use a balanced, water-soluble cactus fertilizer diluted to half strength; apply monthly during the growing season (spring and summer); avoid fertilizing in fall and winter.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicEspostoa melanostele is non-toxic to cats. The main concern is physical injury from its spines.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if touched
Dogs
Non-toxicEspostoa melanostele is non-toxic to dogs. The primary risk is mechanical injury from its spines.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if touched
Humans
Non-toxicEspostoa melanostele is generally non-toxic to humans. However, its sharp spines can cause mechanical injury upon contact.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if touched
Frequently Asked Questions
Q: How often should I water Espostoa melanostele?
A: Water sparingly, only when the soil is completely dry, typically every 2-3 weeks during growing season.
Q: Does this cactus need full sun?
A: Yes, it thrives in bright, direct sunlight but can tolerate partial shade.
Q: Why are the spines falling off?
A: This may indicate overwatering or physical damage; ensure proper care and handling.
Quick Reference
| Family: | Cactaceae |
| Care: | moderate |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during growi |
Get Expert Care Tips
Download the Plantious app for personalized care reminders and plant identification!
Google Play App Store
