Nettle-leaved spurge
cnidoscolus urens
Also known as: ["Nettle spurge","Nettle tree"]
Overview
A spurge species native to the Americas, known for its stinging hairs and toxic sap.
Benefits & Perks
["drought tolerant","wildlife attractant (bees, butterflies, birds)"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Malpighiales |
| Family: | Euphorbiaceae |
| Genus: | Cnidoscolus |
| Botanical Name: | Cnidoscolus urens |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: outdoor garden in warm climates, or indoor pot with bright, direct light
- Suitable For:
- Is Weed: No
- Allergenicity: high
Environmental Needs
- Climate: {"temperatureRange":"10–35°C"}
- Hardiness: {"zones":"9–11"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent waterlogging and root rot.
- Soil Type: Well-draining mix of cactus soil with added perlite or coarse sand for aeration.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Every 2–3 months or as needed to remove damaged or overgrown stems.
- Pruning Intensity: Moderate; remove up to one-third of growth if plant becomes overgrown.
Care Details
Ideal Sunlight Coverage:
Bright indirect light for 6–8 hours daily; can tolerate direct morning sun but avoid harsh afternoon sun.
Sunlight Tolerance Tips:
Acclimate gradually to direct sun; protect from intense midday rays; adjust placement based on seasonal light changes.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
full sun to partial shade
Rotate plant weekly for even growth; use sheer curtains to filter intense light; avoid drafty windows.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly but infrequently; ensure soil dries between waterings; avoid wetting leaves to prevent fungal issues.
Soil
well-draining, sandy loam with some organic matter
pH: Slightly acidic to neutral (pH 6.0–7.0).
Ensure pots have drainage holes; avoid heavy clay soils; topdress with compost annually.
Temperature
Prefers 65–85°F (18–29°C); tolerates mild fluctuations but avoid prolonged exposure to extremes.
Avoid placing near drafty areas; use a thermometer to monitor microclimates; adjust watering with temperature changes.
Fertilizing
every 4–6 weeks during growing season, none in winter
Fertilize only when actively growing; flush soil occasionally to prevent salt buildup; avoid overfertilizing.
Propagation
Methods
Stem cuttings in spring/summer; leaf cuttings can also be used but are less reliable.
Step-by-Step Propagation Guide
- Take a 4–6 inch cutting.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Maintain humidity.
Best Time: Spring or early summer when the plant is actively growing.
Environment
High humidity (70–80%), warm temperatures (70–75°F), and indirect light.
Medium
Well-draining mix of perlite and peat moss or cactus soil.
Hormone
Recommended to use rooting hormone for faster and more reliable rooting.
Timeline
Roots develop in 3–6 weeks; new growth appears in 2–3 months.
Tools Needed
Pruning shears, rooting hormone, small pots, humidity dome, misting spray bottle.
Quick Tips
Use healthy, non-flowering stems; keep soil consistently moist but not waterlogged; provide bottom heat if possible.
Pruning & Repotting
Pruning Guide
Method
Selective pruning of stems to maintain shape; pinch back tips for denser growth.
Pruning Plan
Remove dead or leggy growth to encourage bushier form; shape as needed to maintain aesthetic appeal.
Tools
Clean, sharp pruning shears or scissors; gloves to protect from spines.
Checklist
Disinfect tools; prune during active growth; remove dead/damaged parts; shape evenly.
Repotting Guide
Best Season
Spring, before the active growing season begins.
Pot Size
Increase pot size by 2–3 inches in diameter; ensure good drainage holes.
Method
Remove plant gently; trim roots if necessary; place in a new pot with fresh soil; water lightly.
Suggestions
Repot every 2–3 years or when roots fill the pot; beneficial to refresh soil and provide space.
Checklist
Check root bound status; prepare new pot with drainage; use fresh soil mix; water after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture; water deeply; ensure drainage; avoid leaf wetting.
How to Apply Water Properly
Water directly at the root zone until water drains from the bottom; ensure even saturation without waterlogging; water in the morning to allow foliage to dry.
Watering Schedule Tips
Water deeply once the top inch of soil feels dry; reduce frequency in winter to prevent root rot.
Soil Improvement
Add perlite or coarse sand to improve drainage; incorporate organic matter like compost for fertility.
Temperature Stress Management
Signs of Temperature Issues
Wilting, leaf drop, or yellowing in cold; scorching or stunted growth in excessive heat.
Cold Stress
Slows growth, causes leaf discoloration, and may lead to root rot due to reduced evaporation.
Solution: Move to a warmer location; insulate pots; avoid overwatering in cold conditions.
Hot Stress
Leaves may scorch, wilt, or drop; soil dries out rapidly, increasing water stress.
Solution: Provide shade during peak heat; increase humidity; water more frequently but avoid waterlogging.
Fertilizing Guide
Fertilizing Checklist
Check growth phase; dilute fertilizer correctly; apply to moist soil; avoid contact with leaves.
Fertilizing Method
Use balanced liquid fertilizer diluted to half strength every 4–6 weeks during growing season (spring/summer); cease in fall/winter.
Common Problems & Solutions
Toxicity Warning
Cats
ToxicCats are susceptible to toxicity from Cnidoscolus urens upon ingestion. The plant's irritant compounds and physical spines can cause severe gastrointestinal distress and oral irritation, potentially leading to dehydration and systemic effects.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
ToxicIngestion of Cnidoscolus urens by dogs can cause significant gastrointestinal upset and irritation due to the plant's saponins and calcium oxalate crystals. The plant's spines can also cause mechanical injury to the mouth and digestive tract.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
ToxicCnidoscolus urens, commonly known as Bull Nettle or Tread-softly, contains triterpenoid saponins and needle-like calcium oxalate crystals that cause severe irritation upon contact. Ingestion can lead to gastrointestinal distress and systemic effects due to the plant's irritant compounds.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if touched or eaten
Frequently Asked Questions
Q: Is Cnidoscolus urens safe to touch?
A: No, it has stinging hairs and toxic sap that can cause skin irritation and allergic reactions.
Q: Can Cnidoscolus urens be grown indoors?
A: It is primarily an outdoor plant due to its size and potential hazards.
Q: Does Cnidoscolus urens attract wildlife?
A: Yes, it attracts bees, butterflies, and birds.
Quick Reference
| Family: | Euphorbiaceae |
| Care: | moderate |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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