The Amorphophallus gigas, often called the “giant voodoo lily” or “giant corpse flower,” is known for its immense size and unique flowering habit. Its most infamous trait is the powerful, decaying scent it emits during its brief bloom. This botanical marvel presents a fascinating challenge and reward for dedicated growers.
Understanding Amorphophallus gigas
The Amorphophallus gigas originates from the tropical rainforests of Sumatra, Indonesia, thriving in environments with high humidity, ample rainfall, and moist, well-draining soil at lower elevations. Its single, umbrella-like leaf can reach impressive dimensions, with petioles growing up to 9-13 feet tall and the leaf blade spreading up to 13 feet across. The underground corm, a tuber, can become quite massive, second in size only to A. titanum, potentially weighing up to 70 kilograms (154 pounds).
The plant’s life cycle involves three distinct phases: vegetative, dormant, and generative (flowering). During the vegetative stage, the plant produces its large leaf, capturing energy and storing it in the corm. After several months, the leaf naturally dies back, and the plant enters a dormant period, surviving as the underground corm. The generative phase occurs when the mature corm produces an inflorescence, bypassing leaf production.
The common name “corpse flower” stems from the potent scent emitted by the inflorescence during bloom. This odor, resembling rotting flesh, serves a biological purpose: attracting natural pollinators like carrion beetles and flesh flies. The inflorescence also generates heat, mimicking a decaying carcass, further enhancing scent dispersal and attracting insects.
It is important to differentiate Amorphophallus gigas from its relative, Amorphophallus titanum. Both are “corpse flowers” native to Sumatra with a foul odor. However, A. gigas has the tallest unbranched inflorescence in the world, reaching over 14 feet (4.3 meters). A. titanum typically has a larger inflorescence in overall volume and girth, not sheer height. A. gigas may also flower more frequently under optimal conditions than A. titanum.
Cultivating Amorphophallus gigas
Successful cultivation of Amorphophallus gigas requires replicating its native Sumatran rainforest environment. The plant thrives in bright, indirect light, mimicking dappled sunlight under a dense canopy. While it tolerates partial shade, direct midday sun can scorch its large leaves.
Maintaining a consistently warm environment is important for Amorphophallus gigas. Ideal temperatures range from 70-85°F (21-30°C). Temperatures should not consistently drop below 60°F, as cooler conditions hinder growth and overall plant health.
High humidity is crucial for this tropical plant. An environment with 65-85% relative humidity supports healthy growth. Insufficient humidity can cause leaf petioles to curl downwards. Regular misting or placing the plant near a humidifier helps maintain moisture levels, preventing stress.
The proper soil mix is fundamental for Amorphophallus gigas, requiring excellent drainage while retaining some moisture. A well-draining, rich organic potting mix is suitable, often composed of loam, sand, and organic matter. Many growers use a blend of equal parts peat, perlite, and orchid bark, or approximately 70% perlite to 30% coco coir. This prevents waterlogging, which can be detrimental to the corm, while providing aeration for root development.
During its active growth phase, Amorphophallus gigas requires consistent watering. Keep the soil damp but never waterlogged. Water frequently while the plant is actively leafing out, allowing the top inch of soil to dry slightly between waterings. Do not let the soil dry out completely for extended periods, as this stresses the plant. Proper drainage is paramount to prevent corm rot.
Regular fertilization supports the rapid growth of Amorphophallus gigas. During the growing season, apply a balanced fertilizer every 4-6 weeks, or a diluted phosphorous-rich fertilizer with every other watering. Some growers integrate slow-release fertilizers into the soil mix at half strength every six months. Monitor the plant’s response, as over-fertilization can lead to nutrient burn.
Managing the Amorphophallus gigas Lifecycle
The unique growth cycle of Amorphophallus gigas involves distinct vegetative, dormant, and flowering phases. The vegetative stage begins with a new leaf emerging from the corm, growing to immense sizes, capturing energy, and storing it in the underground tuber. This growth period is when the plant is most active and requires consistent moisture and nutrients.
As the growing season concludes, signaled by reduced light and humidity, the large leaf will naturally yellow and die back. This marks the dormancy phase, where the corm rests underground, conserving energy. During dormancy, reduce watering significantly to prevent rot, allowing the soil to dry out almost completely. Some growers store the corm in a cool, dark, slightly moist environment, like a box with damp sphagnum moss, until new growth emerges.
Repotting is best performed during dormancy, before new growth begins. This allows for corm inspection and moving it into a larger container if needed. The new pot should be approximately 2.5 times wider than the corm, allowing ample space. When repotting, avoid bruising or damaging the corm, as this can lead to rot.
The flowering phase occurs when the corm has stored sufficient energy, often after several years of vegetative growth. Flowering can occur when the corm reaches approximately 10 kg, though in tropical climates, it can reach up to 70 kg. Instead of a leaf, the corm sends up a towering inflorescence, reaching over 11 feet.
This bloom typically lasts only a few days, emitting its foul odor to attract pollinators. The inflorescence can grow rapidly, up to 10 inches per day. After flowering, the plant usually enters another dormancy period before resuming its vegetative cycle.
Common Challenges and Solutions
Even with careful cultivation, Amorphophallus gigas growers may encounter challenges. Corm rot is a common issue, often from overwatering or inadequate drainage. Symptoms include soft, mushy spots on the corm, or the plant failing to produce a leaf or flower, or premature yellowing of foliage. If detected, carefully carve out affected areas until only firm, healthy tissue remains. Dust the wound with sulfur fungicide powder and allow it to dry and scarify in a sunny, well-ventilated area before replanting in fresh, well-draining soil.
Pests like spider mites and mealybugs can pose a threat, leading to stunted growth or discolored foliage. Regular inspection of leaves, especially the undersides, helps early detection. Treatment involves horticultural oil or insecticidal soap applications for thorough coverage. Maintaining high humidity can also deter spider mites, as they prefer drier conditions.
Slow growth or a plant not thriving can be attributed to inadequate light, insufficient humidity, or a lack of nutrients. Ensuring the plant receives bright, indirect light, consistently high humidity (65-85%), and regular feeding during its active growth phase can often resolve these issues. Sometimes, a plant may simply be focusing its energy on root development rather than above-ground growth, especially after repotting.
A corm failing to produce a leaf or flower often indicates it has not stored enough energy or its dormancy period was not managed correctly. Ensuring the corm reaches a sufficient size (ideally 10 kg or more for flowering) and providing a proper, cool, and dry dormancy period are important. If the corm is healthy but not emerging, patience is often the best solution, as it may take time to initiate new growth, sometimes even after several months or a year.
Prevention through proper care is the most effective strategy for mitigating these challenges. Adhering to guidelines for light, temperature, humidity, soil composition, and watering schedules significantly reduces the likelihood of rot, pest infestations, or general growth issues. Regular monitoring of the plant’s condition allows for early intervention, addressing problems before they become severe.