Giant taro root is a striking tropical plant, recognized for its imposing size and bold foliage. Often cultivated for its ornamental appeal, it creates a dramatic statement in gardens and indoor spaces. Known by common names like elephant ear and giant alocasia, it stands out with expansive leaves. Beyond its decorative qualities, some cultures consume its corms and stems as a food source. This plant thrives in warm, humid environments.
What is Giant Taro Root?
Giant taro root, botanically Alocasia macrorrhizos, belongs to the Araceae family. This rhizomatous perennial is known by common names such as giant alocasia and elephant ear. Its native range spans the rainforests of Maritime Southeast Asia, New Guinea, and Queensland, though it has naturalized globally.
The plant is distinguished by its remarkably large, glossy, arrow-shaped leaves, which can extend up to 6 feet long and 2 to 4 feet wide. These impressive leaves feature prominent veins and wavy edges, rising on sturdy, upright stems. Unlike some related species, Alocasia macrorrhizos leaves typically point skyward. The plant develops a thick, stout upright trunk up to 6 feet tall, from which leaf stalks emerge.
Under optimal growing conditions, the plant commonly reaches heights of 12 to 15 feet with a spread of 6 to 10 feet. It can increase its height by 3 to 5 feet annually. Its substantial underground corm and rhizomatous nature contribute to its robust growth and ability to form large clumps.
Edibility and Safe Preparation
Giant taro root, while used as a food source in some cultures, contains calcium oxalate crystals throughout all its parts. These needle-like crystals, known as raphides, cause significant irritation if ingested raw or improperly prepared. Symptoms include a burning sensation in the mouth, tongue, and throat, often described as feeling like hundreds of small needles, along with salivation and swelling.
For safe consumption, giant taro must be thoroughly cooked, as heat breaks down the calcium oxalate crystals. Prolonged boiling is an effective method to neutralize these irritants, making the corms and stems safe to eat. Drying the plant thoroughly is another method that renders it safe. The basal part of the stem is peeled before cooking.
The corms and basal stem are the primary sections consumed. After preparation, corms can serve as a potato-like substitute, and peeled stems are used as a cooked vegetable, often added to soups and stews. In some regions, the stem pith is boiled, dried, and ground into flour. While certain cultivars may have edible leaves and stalks, these also require thorough cooking.
Direct skin contact with the sap can cause itchiness, and eye contact may result in temporary blindness. Therefore, wearing gloves when handling raw giant taro is advisable. Individuals with conditions such as rheumatism, arthritis, gout, or kidney stones should exercise particular caution when considering this plant in their diet. Proper processing is essential to avoid adverse reactions.
Growing Giant Taro Root
Cultivating giant taro root requires specific environmental conditions. This tropical plant thrives in warm, humid climates and is not frost-tolerant, making it suitable for USDA Zones 9 to 11. It prefers partial shade outdoors but can adapt to full sun if gradually acclimated and provided with ample moisture. Indoors, bright, indirect light is preferable.
The plant needs rich, well-draining soil that remains consistently moist but not waterlogged. An ideal soil mix combines organic compost with peat, perlite, or vermiculite to ensure good drainage and aeration. The soil pH should range from 5.7 to 6.3, leaning towards slightly acidic to neutral. Water when the top inch of soil feels dry, increasing frequency in warmer months and reducing it in fall and winter.
Propagation of giant taro is achieved through the division of its corms or rhizomes, with spring or early summer being the optimal time. Each divided section should possess at least one growing point and a portion of the root system for successful establishment. Fertilize with a balanced, water-soluble product every four to six weeks during the active growing season.
Maintaining high humidity, above 60%, is beneficial for this tropical species; indoors, this can be achieved with regular misting or a humidifier. Protection from strong winds is advisable to prevent damage to its large leaves. Care also includes pruning any yellowing or damaged leaves and repotting every one to two years as the plant expands. Corms take 400 to 600 days to mature for harvest.
Distinguishing Giant Taro from Common Taro
Differentiating giant taro (Alocasia macrorrhizos) from common taro (Colocasia esculenta) relies on visual cues. A primary distinction is leaf attachment: Alocasia macrorrhizos leaves point upward, with the leaf stalk connecting directly at the leaf’s notch or edge. In contrast, Colocasia esculenta leaves droop downward, as their stalks attach further within the leaf blade, creating a peltate appearance.
Alocasia macrorrhizos grows taller, reaching 15 feet, compared to most Colocasia varieties (3 to 8 feet). Alocasia leaves have a glossy, waxy texture, while Colocasia leaves have a matte finish. Recognizing these physical differences aids identification for cultivation or consumption.