Elephant's-Ear Alocasia

Alocasia is a genus of 80 species of tuberous, herbaceous perennials in the Arum family (Araceae) from the tropical and subtropical regions of Asia and eastern Australia where rainfall is plentiful. Here it is grown as an ornamental indoor houseplant, or it may be grown outdoors during warmer months in a container or as a border plant. The plants of this genus have colorful, large, heart-shaped or arrow-shaped leaves that resemble elephant ears and measure 12 to 36 inches long. The leaf color, size, and shape vary depending on the species or cultivar. The leaves frequently have distinctive veining. The inflorescence is a creamy white, unbranched spadix of tiny flowers surrounded by a leaflike, hooded spathe. The size of the plants will also vary. In tropical areas the plant can reach up to 10 feet tall; whereas, an indoor houseplant will be much smaller.

Elephant's Ear grows best where annual daytime temperatures range from 68 to 77 degrees Fahrenheit. The plant prefers a shaded site with slightly acidic, moist, well-drained, humus-rich, fertile loam, though it does tolerate a wide range of soil types. Corms may be started indoors in pots or containers and set outside after the last frost date. Water and fertilize regularly. Plants can typically take up to 600 days to mature. Before the first fall frost, dig up the pots and bring them inside where they can be overwintered. Reduce watering in winter and return to the garden in spring. The tubers can also be removed from the soil and stored in a cool, dry location during the winter. The plants can be propagated by division of offsets.

Many species of this plant are thermogenic, meaning that the spadix heats up when the flowers are open. This heat increases the aroma released by the plant, attracting more pollinating insects and keeping them active.

There are many ways to display these plants. Small plants are often found as indoor houseplants. Larger specimens could be displayed as a floor plant in an office or lobby. If temperatures and moisture levels permit, the plant could be used as a summer ornamental on a patio or shady border. However, if grown in a pot, the plant will typically not reach its full height. Use this plant with caution around small children and pets.

Diseases, Pests, and Other Plant Problems:  Alocasia are prone to spider mites. Monitor for aphids and mealybugs. Root rot and leaf spots can occur from overwatering. Yellowing leaves can occur from overwatering, too little water, or inadequate light. The plant is susceptible to high winds, and if sited outdoors, should be in a protected area. Some Alocasia species are considered invasive in the United States, particularly along the Gulf Coast.