Devil's Tongue
Amorphophallus konjac
Amorphophallus konjac, commonly known as Devil's Tongue, is a unique and striking plant native to Southeast Asia. Renowned for its unusual flower and large leaves, it captivates plant enthusiasts and collectors alike.
Everything it needs
9 essentials at a glance
Watering
Amorphophallus konjac prefers to be kept moist but not soggy.
Water thoroughly when the top inch of soil feels dry, approximately once a week during the growing season. In winter, reduce watering to once every two to three weeks. Signs of over-watering include yellowing leaves and root rot, while under-watering may cause wilting and leaf drop.
Light
This plant thrives in bright, indirect light but can tolerate partial shade.
Ideally, place it near a window where it receives filtered sunlight for about 4-6 hours a day. Avoid direct sunlight, which can scorch the leaves, and ensure it has some shade during the hottest part of the day.
Soil
Amorphophallus konjac prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of potting soil, perlite, and orchid bark is recommended to ensure good drainage. The soil should retain some moisture but not become waterlogged.
Humidity
This plant enjoys high humidity levels of around 60-80%.
To increase humidity, consider using a humidifier, placing a tray of water near the plant, or misting the leaves regularly. Signs of low humidity include browning leaf tips and curling leaves.
Temperature
The ideal temperature range for Amorphophallus konjac is between 65-80°F (18-27°C).
It is hardy in zones 7-10 and can tolerate brief periods of cooler temperatures but should be protected from frost. During the growing season, maintain warmer temperatures, while slightly cooler conditions are acceptable in winter.
Fertilizing
Use a balanced liquid fertilizer with an NPK ratio of 10-10-10 during the growing season, applying every 4-6 weeks.
Reduce fertilization in the fall and winter months. Signs of nutrient deficiency include stunted growth and yellowing leaves.
Pruning
Pruning is minimal for Amorphophallus konjac.
Remove any dead or yellowing leaves as needed to maintain appearance. Use clean, sharp scissors or pruning shears to avoid introducing disease. Deadheading is not necessary since the plant primarily produces a single flower spike.
Repotting
Repot every 2-3 years or when the plant outgrows its pot, typically in spring.
Choose a pot that is 1-2 inches larger in diameter. Signs it needs repotting include roots growing out of the drainage holes and stunted growth. To repot, gently remove the plant from its pot, loosen the roots, and place it in fresh soil.
Propagation
Propagation can be done through offsets or corm division.
The best time to propagate is in spring when the plant is actively growing. Carefully remove the corm from the soil, ensuring it has a few healthy roots attached. Cut the corm into sections, each with at least one growing eye, and allow the cut surfaces to dry for a day before planting them in moist soil.
When it's unhappy
Yellow leaves
Why it happens
Often caused by over-watering or insufficient light.
How to fix it
Adjust watering frequency and ensure the plant receives adequate light.
Root rot
Why it happens
Excess moisture in the soil leading to fungal infections.
How to fix it
Allow the soil to dry out and improve drainage; consider repotting in fresh soil.
Browning leaf tips
Why it happens
Low humidity levels or underwatering.
How to fix it
Increase humidity through misting or using a humidifier and adjust watering habits.
Wilting leaves
Why it happens
Under-watering or sudden temperature changes.
How to fix it
Check soil moisture and water thoroughly; maintain stable temperatures.
Pest infestations (e.g., aphids, spider mites)
Why it happens
Poor air circulation or high humidity.
How to fix it
Inspect regularly, remove pests manually or treat with insecticidal soap.
Care through the year
Spring
In spring, increase watering as the plant begins to grow actively. Fertilize every 4-6 weeks with a balanced fertilizer to support new growth.
Summer
During summer, maintain consistent moisture and provide bright, indirect light. Monitor humidity levels and mist regularly to keep the plant thriving.
Fall
In fall, gradually reduce watering as the plant prepares for dormancy. Stop fertilizing and allow the leaves to die back naturally.
Winter
In winter, minimize watering to every two to three weeks. Keep the plant in a cool location away from drafts, and avoid fertilization until spring.
Toxicity & Safety
Amorphophallus konjac is considered toxic if ingested, particularly the corms, which can cause gastrointestinal distress in pets and children. Symptoms may include vomiting, diarrhea, and abdominal pain.
Good to know
Why are my Amorphophallus konjac leaves turning yellow?
Yellow leaves can indicate over-watering or insufficient light. Ensure you are watering only when the top inch of soil is dry and that the plant is receiving bright, indirect light.
How often should I water my Devil's Tongue plant?
Water your Amorphophallus konjac once a week during the growing season, allowing the top inch of soil to dry out between waterings. In winter, reduce watering to every two to three weeks.
What type of soil is best for Amorphophallus konjac?
A well-draining soil mix is ideal, with a combination of potting soil, perlite, and orchid bark. The pH should range from 6.0 to 7.0 to promote healthy growth.
How do I increase humidity for my Devil's Tongue plant?
To increase humidity, use a humidifier, place a tray of water near the plant, or mist the leaves regularly. Aim for humidity levels around 60-80% for optimal growth.
When is the best time to repot Amorphophallus konjac?
The best time to repot is in spring when the plant is actively growing. Look for signs such as roots growing out of the drainage holes or stunted growth.
Is Amorphophallus konjac toxic to pets?
Yes, Amorphophallus konjac is toxic if ingested, particularly the corms. Symptoms may include vomiting and diarrhea, so keep it out of reach of pets and children.
How can I propagate my Devil's Tongue plant?
You can propagate Amorphophallus konjac through offsets or corm division in spring. Ensure each section has a growing eye, and allow the cut surfaces to dry before planting.
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