Konjac (Amorphophallus rivieri var. konjac)

Konjac

Amorphophallus rivieri var. konjac

Its huge, dramatic leaf unfurls like a giant umbrella, hiding a pungent bloom underground. Tuberous herbaceous perennial; common names: konjac, devil's tongue.

Partial sun
1–2/week
Moderate
🌱

Plant Needs

☀️
Sunlight Bright indirect light with partial shade during midday to prevent leaf scorching; tolerates low light during dormancy
💧
Watering Water thoroughly when the top 5 cm of soil dries out; avoid overwatering to prevent tuber rot
🌡️
Temperature Thrives in temperatures between 18–25°C; protect from frost and temperatures below 10°C during dormancy
🔍

Characteristics

  • Leaf: Single large, deeply divided compound leaf on thick, spotted stalk; resembles a small tree canopy
  • Flower: Rare pungent spadix enclosed in a burgundy spathe; emits foul odor to attract pollinators
  • Tuber: Large, starchy underground storage structure with rough, brown, textured skin
🛠️

Care Guide

Watering

Keep soil consistently moist during active leaf growth

Fertilization

Diluted balanced liquid fertilizer every 2 weeks. Stop fertilizing once the leaf starts to yellow and dormancy begins

Eggshell powder top dressing:Sprinkle 1–2 tablespoons of finely crushed eggshell powder around the base of the plant every 2 months; avoid direct contact with the tuber
Pruning
  • Trim yellowing or damaged leaf stalks at the base once they fully die back during dormancy
  • Remove soft, rotting sections of the tuber during repotting to prevent spread of decay
  • Cut back spent flower stalks immediately after blooming to conserve tuber energy
⚠️

Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA confirmed toxic; calcium oxalate crystals cause oral and gastrointestinal irritation

Humans: Raw tubers contain calcium oxalate crystals causing oral irritation; fully cooked tubers are non-toxic and edible

📖

Garden Uses & Culture

Culture: N/A

Usage: Processed tuber used to make konjac jelly and shirataki noodles; ornamental foliage plant for large indoor spaces