Giant elephant's ear (Alocasia macrorrhizos)
Grow the commanding Alocasia macrorrhizos, or Giant elephant's ear, for tropical impact. Hardy in Zones 9-11, needing part shade and moist soil.
Complete Plant Information
Overview
The Alocasia macrorrhizos, widely known as Giant elephant’s ear, is an outstanding architectural plant prized for its massive, deeply veined foliage that creates instant tropical drama in the landscape. This rhizomatous perennial stands tall, often reaching heights of 12 to 15 feet, making it a significant focal point plant where hardy. While treasured for its imposing look, this plant also holds cultural significance as giant taro, with edible, though toxic when raw, rhizomes cultivated in tropical regions.
This species thrives as a bold statement piece, needing protection from harsh light and heavy winds to keep its monumental leaves pristine. Alocasia macrorrhizos is a forest understory native, lending clues to its preference for filtered sunlight over scorching full exposure. Gardeners outside its tropical range can still enjoy the majesty of the Giant elephant’s ear by treating it as a spectacular annual or overwintering the rhizomes indoors.
Growing Alocasia macrorrhizos requires a commitment to consistent moisture, as its water needs range from medium to thoroughly wet, reflecting its origins in humid environments. Proper placement ensures the upright leaves are supported and showcased, adding vertical interest to garden designs where conditions are reliably warm and damp.
Fast Facts
- Plant Family: Araceae
- Plant Type: Bulb
- Native Range: Australia, Malesia, Papuasia
- Hardiness Zones: USDA Zones 9-11
- Size at Maturity:
- Height: 12-15 ft
- Spread: 6-8 ft
- Bloom Time: Seasonal bloomer
- Bloom Description: Greenish-white
- Sun Exposure: Part shade
- Water Needs: Medium to wet
- Maintenance Level: Medium
How to Grow
Planting Alocasia macrorrhizos should occur in spring once all danger of frost has passed, setting the rhizomes in organically rich soil amended to ensure moisture retention. In warmer climates (Zones 9-11), choose a deeply sheltered spot where it receives part shade or bright, filtered sunlight; foliage scorches easily in direct afternoon sun. If growing in areas prone to frost, containers are ideal, allowing the plant to be moved indoors before the first autumn chill.
Consistent moisture is critical for this tropical giant; plan for regular watering to maintain medium to wet soil conditions, and do not hesitate to place plants where they might receive periodic flooding, as Alocasia macrorrhizos handles wet feet well. Ample fertilization throughout the growing season supports the rapid production of the enormous leaves that define this plant. Be aware that insufficient light causes the petioles to weaken, eventually failing to support the weight of the leaves.
For overwintering non-hardy stock, bring containerized Giant elephant’s ear indoors before temperatures drop near freezing. Keep them cool (around 60-65°F), place them in a bright location, and significantly reduce watering until spring. As spring approaches and frost risk passes, harden off the plants before sinking the containers into the garden or patio display.
Landscape Uses
The sheer scale of Alocasia macrorrhizos makes it an unparalleled choice for creating instant, dense tropical effects in frost-free gardens. Use it as a dramatic backdrop specimen, or mass several plants together to form an imposing, living screen. In containers, the Giant elephant’s ear commands attention on patios or flanking an entryway where its architectural form can be fully appreciated.
For designers aiming for a jungle aesthetic, pair this plant with broad-leafed companions like Bananas (Musa) or large ferns that share similar cultural demands for moisture and filtered light. In cooler regions where it must be grown as an annual or houseplant, its container growth allows it to provide vertical height during the summer months before transitioning indoors for winter shelter.
Standout Features
Flower Qualities
- Showy
Fruit Qualities
- Showy
Noteworthy Characteristics
The Alocasia macrorrhizos is distinguished by its signature upright leaves, which differ from the lower-hanging foliage typical of related genera like Colocasia. This rhizomatous perennial is valued not only for its massive, cordate green leaves—which can reach up to 4 feet wide—but also historically for its rhizomes, which serve as an edible taro staple when properly cooked to neutralize calcium oxalates. Its genus name hints at its historical differentiation, being separated from Colocasia, while the species epithet highlights its large root system.
Tolerances
- Wet Soil
Potential Problems
The large, lush leaves of the Giant elephant’s ear can attract common house and garden pests when grown in less-than-ideal conditions, particularly indoors or in dry spells. Watch diligently for signs of spider mites, which thrive in dry air, as well as scale insects, mealybugs, and aphids clustering on stems and leaf undersides. Maintaining high humidity, especially for indoor specimens, is crucial for prevention. Regularly inspect leaves and stems; treatment often involves horticultural oils or insecticidal soap applied directly to the pests.
Frequently Asked Questions
What hardiness zones is Giant elephant’s ear suitable for?
Alocasia macrorrhizos is winter hardy in USDA Zones 9 through 11, requiring protection or overwintering when grown in colder regions.
How large does Giant elephant’s ear grow?
This plant is notable for its stature, reaching heights between 12 and 15 feet tall with a spread ranging from 6 to 8 feet wide in ideal conditions.
What sun exposure does Alocasia macrorrhizos need?
Alocasia macrorrhizos performs best in part shade; strong, direct sun will often scorch the large ornamental leaves.
When does the Giant elephant’s ear bloom?
It is a seasonal bloomer, producing infrequent, not particularly showy, greenish-white spathes and spadices.
Conclusion
The Alocasia macrorrhizos stands unmatched for instant tropical scale and bold texture, easily becoming the centerpiece of any garden space it occupies. Whether utilized as a monumental perennial in Zones 9-11 or skillfully overwintered as a container specimen, the Giant elephant’s ear delivers dramatic visual impact. Before planting, confirm your location sits within the correct hardiness range or prepare a suitable indoor space for winter, ensuring consistent moisture to support its magnificent growth.
Companion Planting
Selecting appropriate companions for Alocasia macrorrhizos helps achieve a unified tropical look while maintaining shared cultural needs. Look for other plants that appreciate moist, rich soil and prefer the shelter of part shade. Good pairings include large-leafed Hostas (in shadier spots), Cannas, Caladiums, or other humidity-loving Aroids that do not aggressively compete for root space. Avoid placing it directly against structures that might block necessary air circulation, as stagnant air can encourage pests.
Propagation Tips
While Alocasia macrorrhizos can be propagated by reddish seeds that form on the spadix, the fastest and most practical method for home gardeners involves division. Wait until spring when preparing to repot or transplant; carefully examine the base of the mature plant for offsets or rhizomes that have formed separately from the main clump. Gently separate these smaller rhizomes using a clean, sharp spade or knife, ensuring each division has at least one viable growth point or section of the stout trunk. Pot these divisions individually into a moist, well-draining medium and keep them warm until active growth resumes.
