Culture
This tropical aroid is winter hardy to USDA Zones 8-10. In the St. Louis area, it must be grown as an annual and repurchased each spring or overwintered indoors. It is best grown in rich, deep, moist but well-drained soils in part shade. Leaves may bleach or scorch in full sun. White variegation may become dull in too much shade. Site in locations protected from strong wind. This plant thrives in hot and humid conditions as long as it receives consistent moisture. Tuberous rhizomes should be planted in spring after the last frost date. Rhizomes may be planted directly in the ground (about 18” apart) or in large containers that may be placed above ground or sunk into the ground. Dig up rhizomes in fall before first frost for overwintering indoors in a cool, dry place (in the same manner as for cannas). Container plants may be brought indoors before frost for overwintering in a cool location either as a houseplant with reduced watering or as a cut back dormant plant.
Noteworthy Characteristics
Xanthosoma is an herbaceous perennial from tropical America. It is closely related to Colocasia and Caladium. It is grown for its bold, tropical foliage.
Genus name comes from the Greek words xanthos meaning yellow and soma meaning a body with reference to the yellow inner tissues of some species.
Specific epithet means dark green.
'Variegatum Monstrosum', knowns as mouse-cup taro, is ornamentally grown in St. Louis for its attractive elephant ear-like green leaves with unusual white variegation. Leaf tips will sometimes form a cup that holds water, at times with tails extending outward from the cup. In tropical climates, plants will grow to 5-7’ tall with leaves to 2’ long, but will more often grow to 2-3’ tall in one season in Midwestern gardens. From a distance, the variegation on each large leaf purportedly resembles the light and dark patterns found on the cartoon character Mickey Mouse. Flower is a greenish-white spathe enclosing a white spadix, however flowers are infrequently produced.
Problems
Leaf spots and virus may occur. Pythium rot and Rhizoctonia rot. Watch for snails.
Uses
Tropical foliage plant for gardens and patios.