947 Alocasia macrorrhizaCommon Names: giant taro, giant elephant ear, upright elephant ear, pai Family: Araceae (arum Family)
iant taro is a massive perennial with huge elephant ear leaves 3-6 ft (0.9-1.8 m) in length and 2-4 ft (0.6-1.2 m) wide borne on leaf stalks (petioles) 2-4 ft (0.6-1.2 m) long. The petioles emerge from a stout upright trunk that can stand 6 ft (1.8 m) tall. The whole plant can stand 12-15 ft (3.7-4.6 m) tall and spread 6-10 ft (1.8-3.1 m) across. (Truly imposing!) In the typical form the leaves are glossy medium green with paler veins. They are arrow shaped at their bases and stand upright, pointing skyward, unlike other large "elephant ear" perennials. The greenish spathe and spadix (like a "Jack-in-the-pulpit") stands 8-10 in (20.3-25.4 cm) tall and is not particularly showy. 'Variegata' is a selection with leaves decorated with creamy white or grayish splotches. 'Violacea' has pale violet leaves.
Giant taro is similar to other large-leafed arums such as the true elephant ears (Xanthosoma sagittifolium), the arrow arums (Peltrandra spp.), and dasheen (Colocasia esculenta), often called "taro." Giant taro differs from the others in having an upright stem and holding its leaves upright, and in several technical characteristics that mean a lot to the botanists. Numerous hybrids have been produced from among the various elephant ear species, and it's not always possible to identify particular specimens.
Giant taro, Alocasia macrorrhiza occurs naturally in tropical forests in Sri Lanka, India and Malaysia where it grows in the forest understory in openings and along streams.
CultureLight: Partial shade is ideal, and giant taro can tolerate almost full shade. Moisture: Grow taro in moist, but well drained soil that is rich in organic humus. It likes lots of fertilizer. Giant taro thrives in a humid environment, and can tolerate shallow flooding. Giant taro is not at all salt tolerant. Hardiness: USDA Zones 9 - 11. This tropical herbaceous perennial is a little more cold hardy than many of its relatives. Freezing temperatures damage the leaves but the trunk sprouts new ones if it hasn't fallen below about 25ºF (-3.9 ºC). The plant can be given some protection from cold by covering with a blanket and burning a light bulb inside the "tent" thus created. Propagation: The taros spread by rhizomes and these may be cut between the upright stems to yield new plants. Offsets often develop and these too may be separated from the parent plant. Stem cuttings root readily, especially in spring and early summer. The reddish seeds that develop like corn on the cob along the spadix should be planted as soon as they ripen.
Giant taro is a favorite greenhouse plant - at least for people with large greenhouses! If you need a bold and imposing foliage plant for a tropical or subtropical shady background, giant taro fits the bill. It is often grown in wet situations.
Giant taro is cultivated throughout the tropics for its edible rhizomes and shoots. See the true taro profile for a discussion of the culinary properties of these closely related "potatoes of the tropics".
The genus, Alocasia, the elephant ears, has about 70 species, all indigenous to southeast Asia. They are closely related to Colocasia, and were formerly grouped together in a single genus.
All parts of taro can cause stomach aches if ingested without cooking and proper preparation. Contact with the sap can irritate sensitive skin.
Steve Christman 3/16/02; updated 1/9/04, 8/30/07, 3/4/08, 9/12/08