Knuth's Spurge (Euphorbia knuthii)

Knuth's Spurge

Euphorbia knuthii

Its compact spiky form holds sunlit green charm. Succulent perennial shrub; common name: Knuth's Spurge.

Full sun
1/week
Beginner
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Plant Needs

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Sunlight Full sun to partial sun; tolerates bright indirect light indoors; avoid prolonged midday direct sun in hot climates
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Watering Allow soil to dry completely between waterings; avoid overwatering to prevent root rot
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Temperature Thrives at 18–25°C; protect from frost and temperatures below 10°C to avoid tissue damage
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Characteristics

  • Leaf: Small obovate fleshy green leaves clustered at stem tips; drop during drought stress
  • Flower: Tiny yellow cyathia (false flowers) in terminal clusters; lack true petals
  • Stem: Thick green succulent stems containing milky latex sap
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Care Guide

Watering

Water when the top 5 cm of soil is completely dry; avoid waterlogging

Fertilization

Diluted succulent fertilizer once monthly. Use a balanced, low-nitrogen diluted fertilizer to avoid excessive leaf growth

Eggshell powder top dressing:Crush dried eggshells into fine powder; sprinkle a thin layer on soil surface; avoid direct contact with stems to prevent irritation
Pruning
  • Remove dead or yellowing leaves at the base to maintain tidy form
  • Trim overgrown stems in early spring to encourage compact branching
  • Wipe pruning tools thoroughly after use to avoid spreading toxic sap to other plants
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Toxic; ingestion causes vomiting, diarrhea, oral irritation, and hypersalivation

Humans: Milky latex sap causes skin irritation, redness, and blistering on contact; oral ingestion leads to burning discomfort and nausea

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Garden Uses & Culture

Culture: N/A

Usage: Ornamental succulent for rock gardens, container planters, and indoor succulent collections