Alocasia macrorrhizos
Alocasia macrorrhizos (Giant Taro) Care Guide
Featured photoalocasia-macrorrhizos.jpgAlocasia macrorrhizos is the largest commonly grown alocasia, capable of producing arrow-shaped leaves over a metre long on equally tall petioles. In Southeast Asia it is widely cultivated as the food plant taro, although toxic raw. As a houseplant or patio plant it makes a tropical statement in bright rooms with high humidity and steady water.
Care facts at a glance
- Light
- Bright indirect
- Water
- Water when the top 2 to 3 cm of mix has dried; large leaves use water quickly.
- Humidity
- 60–80 %
- Temperature
- 18–30 °C
- Soil
- Rich, well-draining loam with extra perlite or bark; macrorrhizos is a heavier feeder than most alocasias.
- Toxicity
- Toxic raw. Calcium oxalate is destroyed by thorough cooking, but raw plant material burns the mouth. (humans) · Toxic to cats and dogs (ASPCA Alocasia listing). (pets)
- Origin
- Tropical Southeast Asia and the western Pacific.
- Mature size
- 1.5 to 3 metres tall indoors with adequate light, larger outdoors.
Overview
Alocasia macrorrhizos has been cultivated for thousands of years in tropical Asia and the Pacific. As a houseplant it is the genus's giant — a bright living-room corner plant for those with the space, or a summer patio specimen in cooler climates.
Care Priorities
- Plenty of light is essential; in poor light leaves stay small and pale.
- Use a large, heavy pot — macrorrhizos top-heaviness will tip lighter pots.
- Water generously in summer, much less in winter dormancy.
- Feed regularly; this species is a heavier feeder than most alocasias.
Common Problems
Lopsided growth is a light problem; rotate the pot weekly. Sudden leaf collapse is usually overwatering in cool weather. Brown crispy edges signal dry air.
Sources & further reading (3)
- encyclopedia — accessed 2026-04-28
- botanical-garden — accessed 2026-04-28
- toxicity-database — accessed 2026-04-28
Frequently asked questions
Can I eat the corms?
Some cultivars are eaten as taro after thorough cooking, but ornamental clones can have higher oxalate content. Treat indoor plants as ornamental only.
Will it survive a cold draught?
Briefly, but a cold spell at 10 °C or below can trigger leaf drop or worse. Keep it warm.
Difference between macrorrhizos and odora?
Both are giant elephant-ear alocasias; odora is generally smaller, hardier, and has a sweeter flower scent. Macrorrhizos has stiffer, more upright leaves.
