One can ignore large leaves for only so long, and the Alocasia macrorrhiza has big leaves, up to four feet long. As one might suspect, it also has a large root, up to a foot long and half a foot through.
The Giant Taro was first domesticated in the Philippines. Polynesian explorers took the large tuber eastward during their travels carrying it to Hawaii around 1500 years ago. It’s now a major food staple in areas that are too warm or humid to raise traditional starch vegetables such as potatoes. While it is a food crop it escapes from cultivation and becomes naturalized.
Finding a Giant Taro is far more fun than growing one. It takes 18 to 24 months to put on a large root (actually a rhizome.) However, Giant Taro can be harvested nearly any time in the growth cycle though a large mature root will feed an entire family. It propagates by offsets or by cutting up the root. If you are cultivating the species it can be quite demanding requiring rich soil, constant moisture and feeding three times a month. Should you decide to grow one know the root is planted vertically, not horizontally. It can be grown in northern climes but needs to be overwintered inside. And on the plus side is that it is a root crop that will grow in significant shade.
The roots have a potato-like flavor and the white interior of the thick stems can also be eaten. After boiling the cooked stem material is dried then ground into flour. As with most plants in this family the Giant Taro has calcium oxalates, which are needle-shaped crystals. They give an affect of burning if you handle them improperly and can make you ill if you manage to consume them. Cooking breaks down the calcium oxalate making the root and stem material edible. The most common means of preparation is boiling cut up parts of the root.
Alocasia (ah-low-KAY-see-ah) means “like but not Colocasia” that is, like the Taro but not the taro. Macrorrhiza (mak-row-RYE-zah) means large root. The species is also called “Upright Elephant Ears.” Giant Taro is a good source of Vitamin C, phosphorus and iron.
Lastly, in Borneo cooked rice is mixed with yeast and wrapped in Giant Taro leaves to ferment. It’s kept in a cool dry place for a couple of days until the rice is fermented but not alcoholic. You eat the rice not the leaf.
Green Deane’s “Itemized” Plant Profile: Giant Taro
IDENTIFICATION: A massive perennial, huge “elephant ear” leaves 3-6 feet in length, 2-4 feet wide stalks 2-4 feet long. Stalks emerge from an upright trunk to 6-feet tall. Whole plant can be 12-15 feet tall and 6-10 feet wide. Leaves a glossy medium green with paler veins, arrow-shaped at the bases. The leaves stand upright, pointing skyward, unlike other large “elephant ears.” Greenish spathe and spadix (like “Jack-in-the-pulpit”) to ten inches, not particularly showy. Other species: ‘Variegata’ leaves are decorated with creamy white or grayish splotches. ‘Violacea’ has pale violet leaves.
TIME OF YEAR: Edible cooked most of the time though a fully mature root takes two years.
ENVIRONMENT: Partial shade is ideal if not total shade. Moist well-drained soil rich in organic humus. Lots of fertilizer. Thrives in humid environments, can tolerate shallow flooding. Not all salt tolerant. Once established can tolerate a mild frost.
METHOD OF PREPARATION: Roots, or parts of the root, boiled the same as potatoes. Stems pith boiled, dried, ground into flour.