African Milk Tree

euphorbia horrida

Also known as: ["African Milk Plant","Crown of Thorns"]

Family: Euphorbiaceae Genus: Euphorbia Category: Succulents & Cacti

Overview

A succulent species native to South Africa, known for its columnar growth habit and spiny stems.

Benefits & Perks

["drought tolerant","rare/collector’s item"]

Botanical Classification

Phylum: Magnoliophyta
Class: Magnoliopsida
Order: Malpighiales
Family: Euphorbiaceae
Genus: Euphorbia
Botanical Name: Euphorbia horrida

Plant Characteristics

Basic Information
  • Category: Succulents & Cacti
  • Suitable Location: indoor pot in bright, sunny location or outdoor rock garden
  • Suitable For:
    Beginners Busy People (low Maintenance) Collectors & Enthusiasts Outdoor Landscapers
  • Is Weed: No
  • Allergenicity: moderate
Environmental Needs
  • Climate: {"temperatureRange":"5–35°C"}
  • Hardiness: {"zones":"9–11"}
  • Misting: rarely required, only if ambient humidity is very low
  • Drainage: Fast-draining to prevent root rot.
  • Soil Type: Well-draining cactus or succulent mix with added perlite or coarse sand.
Maintenance Level
  • Maintenance Level: low
  • Toughness Level: high
  • Pruning Frequency: As needed, typically every 1–2 years or after flowering.
  • Pruning Intensity: Moderate; remove up to one-third of growth if necessary.
Care Details

Ideal Sunlight Coverage:
Bright indirect light or full sun (4–6 hours/day); adjust to avoid scorching in intense summer sun.

Sunlight Tolerance Tips:
Acclimate gradually to intense light; protect from direct midday sun; place in a spot with filtered light or partial shade during peak heat.

Warning Signs: Wilting despite moist soil (root rot); yellowing or dropping leaves (overwatering or cold stress); stunted growth (poor light or nutrients).

Care Requirements

Care Difficulty
moderate

moderate

Sunlight

full sun to partial shade

Rotate plant weekly for even growth; use sheer curtains to filter intense light; avoid sudden light changes.

Watering

every 7–14 days during growing season, reduce to monthly in winter

Water thoroughly but infrequently; ensure excellent drainage; avoid waterlogged soil.

Soil

well-draining, sandy or gritty cactus mix

pH: Slightly acidic to neutral (pH 6.0–7.0).

Use pots with drainage holes; avoid heavy garden soil; topdress with gravel for extra drainage.

Temperature

Prefers 65–80°F (18–27°C); tolerates mild frost but thrives in warm conditions; reduce watering in cooler months.

Avoid sudden temperature shifts; protect from frost; ensure good air circulation.

Fertilizing

every 4–6 weeks during active growth with diluted cactus fertilizer

Fertilize only during active growth; flush soil occasionally to prevent salt buildup; use a cactus-specific fertilizer.

Propagation

Methods

Stem cuttings or offsets; allow cuttings to callus for several days before planting.

Step-by-Step Propagation Guide
  1. Select healthy stem.
  2. Cut cleanly.
  3. Let callus.
  4. Plant in medium.
  5. Water sparingly.
  6. Provide warmth and light.

Best Time: Spring or early summer when the plant is actively growing.

Environment

Warm, humid environment with indirect light; maintain consistent warmth (70–75°F).

Medium

Well-draining mix of cactus soil and perlite or sand.

Hormone

Optional, but rooting hormone can speed up the process.

Timeline

Roots may form in 2–4 weeks; establish in new pot within 2–3 months.

Tools Needed

Sharp knife or scissors, rooting hormone (optional), small pots, well-draining soil mix.

Quick Tips

Use gloves to handle sap; ensure cuttings are dry before planting; avoid overwatering.

Pruning & Repotting

Pruning Guide
Method

Cut stems cleanly just above a node or junction; wear gloves to avoid sap irritation.

Pruning Plan

Remove dead or damaged stems to maintain shape and health; encourage bushier growth.

Tools

Sharp, sterilized pruning shears, gloves, protective eyewear.

Checklist

Sterilize tools; wear gloves; cut cleanly; dispose of pruned material; clean up spills.

Repotting Guide
Best Season

Spring, before active growth begins.

Pot Size

Increase pot size by 1–2 inches in diameter; ensure the new pot has drainage holes.

Method

Remove plant carefully; trim roots if needed; place in new pot with fresh soil; ensure drainage.

Suggestions

Repot every 2–3 years or when roots fill the pot; necessary to refresh soil and provide space.

Checklist

Prepare new pot; protect skin from sap; water sparingly after repotting; place in appropriate light.

Advanced Care Tips

Watering Mastery
Watering Checklist

Check soil dryness; water deeply; ensure drainage; adjust for season.

How to Apply Water Properly

Water directly at the root zone until water drains from the bottom; ensure excess water exits the pot; water in the morning to allow foliage to dry.

Pro Tip: Use a watering can with a long spout to direct water precisely to the soil, avoiding the spines.
Watering Schedule Tips

Water deeply during active growing season (spring-summer), allowing soil to dry completely between waterings; reduce or cease watering in winter dormancy.

Soil Improvement

Add coarse sand or perlite to commercial potting mix; ensure soil is loose and airy.

Temperature Stress Management
Signs of Temperature Issues

Chlorosis or necrosis in extreme heat; etiolation or weak growth in insufficient light/low temps.

Cold Stress

Slows growth; may cause root rot if soil remains wet; leaves may drop or turn yellow.

Solution: Move to a warmer location; ensure soil is dry; provide protection from drafts or cold windows.

Hot Stress

Leaf scorch or sunburn; wilting despite adequate water; stunted growth.

Solution: Provide shade during peak sun; increase humidity; water early morning or late evening.

Fertilizing Guide
Fertilizing Checklist

Check growth phase; dilute fertilizer; apply to moist soil; avoid contact with roots.

Fertilizing Method

Use a balanced, water-soluble fertilizer diluted to half strength; feed monthly in spring-summer; avoid fertilizing in fall-winter.

Common Problems & Solutions

Yellowing leaves in Euphorbia horrida are not commonly reported, as this species typically retains its green coloration unless suffering from severe stress or nutrient deficiencies.

Wilting in Euphorbia horrida may indicate overwatering, root rot, or extreme environmental stress, as the plant is adapted to arid conditions and generally stores water in its stems.

Leaf spots are not commonly reported on Euphorbia horrida, as the species is more stem-centric and less prone to foliar diseases compared to leafy plants.

Rotting, particularly root or stem rot, can occur in Euphorbia horrida due to excessive moisture or poor drainage, leading to tissue decay and potential plant death.

Toxicity Warning

Cats
Toxic

Cats are susceptible to the toxic effects of Euphorbia horrida upon ingestion. The plant's sap can cause severe irritation to the mouth, throat, and gastrointestinal tract, leading to discomfort and potential systemic effects.

⚠️ Symptoms:
drooling vomiting difficulty swallowing diarrhea lethargy
🌿 Toxic Parts:
milky sap leaves stems
⚡ Toxic If:

if ingested

Prevent cats from accessing the plant. If ingestion is suspected, seek veterinary care promptly. Provide supportive care as advised by a professional.
Dogs
Toxic

Ingestion of Euphorbia horrida by dogs can cause significant gastrointestinal upset due to the plant's irritant compounds. The milky sap can also cause oral and esophageal irritation upon contact.

⚠️ Symptoms:
drooling vomiting diarrhea abdominal pain lethargy
🌿 Toxic Parts:
milky sap leaves stems
⚡ Toxic If:

if ingested

Keep pets away from the plant. If ingestion is suspected, contact a veterinarian immediately. Do not induce vomiting without professional guidance.
Humans
Toxic

The milky sap of Euphorbia horrida contains diterpenoid phorbol esters and other irritants, which can cause severe skin and eye irritation upon contact. Ingestion can lead to gastrointestinal distress and systemic toxicity due to the sap's caustic properties.

⚠️ Symptoms:
skin irritation eye irritation burning sensation nausea vomiting diarrhea
🌿 Toxic Parts:
milky sap leaves stems
⚡ Toxic If:

if touched or ingested

Avoid contact with the sap. Wear gloves when handling. In case of contact, rinse thoroughly with water. Seek medical attention if ingested or if irritation persists.
Important: Keep this plant out of reach of children and pets. If ingestion occurs, contact poison control or veterinary services immediately.

Frequently Asked Questions

Q: Is Euphorbia horrida toxic to pets?

A: Yes, it is toxic to dogs and cats if ingested.

Q: How often should I water Euphorbia horrida?

A: Water sparingly, allowing the soil to dry completely between waterings.

Q: Does Euphorbia horrida require full sun?

A: It thrives in bright, indirect light but can tolerate full sun with proper acclimatization.

Quick Reference
Family: Euphorbiaceae
Care: moderate
Light: full sun to partial shade
Water: every 7–14 days during growi
Suitable For: ["beginners","busy people (low maintenance)","collectors/enthusiasts","outdoor landscapers"]
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