Elephant Ears (Colocasia, Alocasia, and Xanthosoma)

Elephant ears is the common name for a group of tender, tropical perennial plants grown for their large, heart-shaped leaves. Most of these herbaceous species in the arum or aroid family (Araceae) offered as ornamentals belong to the genera Colocasia, Alocasia, and Xanthosoma, although there are other species with similar appearance and growth habits.

The first two genera are native to tropical southern Asia, Indonesia, Malaysia, New Guinea, parts of Australia, or the Pacific Islands, while Xanthosoma is native to tropical America. Many of the species have long been grown for the edible starchy corms (tubers as an important staple food in tropical regions.

The leaves are edible, but they (and all parts of the plant) contain needle-like crystals of calcium oxalate which are a skin irritant, so they must be cooked first.

In Midwestern gardens, these plants are grown for their flat sagittate (arrow- or heart-shaped) leaves that often have prominent veins. In their native habitat the smooth, waxy leaves will grow 3 feet long and 2 feet wide or more (depending on the species) but they tend to be much smaller when grown as a seasonal plant in cold climates.

The leaves are held on the end of long, thick, succulent petioles coming directly from the underground corm. The petiole attaches near the center of the lower surface of the leaf (peltate) and the leaves are held perpendicular to the upright petiole with the leaves facing upward or outward.

• ‘Black Coral’ is in the ROYAL HAWAIIAN® Series. It features huge, glossy all-black, corrugated leaves. It grows 4 feet tall and 3 feet wide.
• ‘Black Magic’ was the first black cultivar introduced. It has dusty purple-black leaves (with green undertones in shady conditions), the blades slightly folded upwards, and dark petioles. It grows 3 to 6 feet tall and wide.
• ‘Blue Hawaii’ (USPP 20,003) is in the ROYAL HAWAIIAN® Series. It has medium green leaves with dark purple-black veins and maroon undersides. It grows 5 feet tall when mature.
• ‘Burgundy Stem’ is a tall cultivar with deep purple petioles topped with big green leaves with a slight purple tinge.
• ‘Coal Miner’ is similar to ‘Illustris’ but is much earlier, does not spread underground as vigorously, the background leaf color is darker, and the leaves have a velvety patina when they first emerge.
• ‘Coffee Cups’ (sometimes incorrectly called ‘Tea Cups’) is a vigorous hybrid with smaller leaves on very tall dark petioles with the blades folded upward to form a cup-shape.
• ‘Diamond Head’ (USPP 19,939) is in the ROYAL HAWAIIAN® series. It is vigorous, with glossy purple, slightly puckered leaves. It grows 4 feet tall and 5 feet wide when mature.
• ‘Elena’ has chartreuse leaves similar to ‘Lime Zinger’ but with cream-colored petioles that change to purple where they join the leaf and veins where the stalk attaches. It will spread by aboveground rhizomes when planted in moist sites.
• ‘Fontanesii’ (violet-stemmed taro) is a tall hybrid with dark green leaves with a shiny black cast on dark petioles.
• ‘Hawaii Calls’ is in the ROYAL HAWAIIAN® series. It features purple leaves with yellowish white margins and light green highlights. Grows 4 feet tall and 3 feet wide when mature.
• ‘Hilo Beauty’ is a small variety (about a foot tall) of Alocasia with irregular yellow or cream flecks on the dark green leaves.
• ‘Illustris’ (imperial taro, var. antiquorum) has dark green matte leaves with a purple to black luster and bright green veins and petioles. The plants spread by underground runners. Color is more intense in bright light, but the leaves are never as dark as ‘Black Magic’ or many other black varieties.
• ‘Jet Black Wonder’ has light-colored veins on a black background.
• ‘Lime Zinger’ is a brilliant chartreuse green Xanthosoma. It grows 4 feet tall and 3 feet wide.
• ‘Mai Tai’ is in the ROYAL HAWAIIAN® series. It has light green leaves variegated with dark green splotches and light colored petioles with purple speckling and striping. Grows 4 feet tall and 3 feet wide.
• ‘Mojito’ (USPP 21,995) has dull green leaves irregularly splotched, speckled, and streaked with black on dark or patterned petioles. It is less vigorous than many others.
• ‘Nancy’s Revenge’ has color changing leaves which start out all green, then develop butter yellow centers at the onset of flowering. The color leaks from the center down the main vein into the surrounding blade to eventually form an oval shape.
• ‘Pink China’ has green leaves on pinkish stems. It is one of the hardiest elephant ears, reports of survival in zone 6b, and further north in protected sites.
• ‘Stingray’ is an Alocasia with a distinct tail on the end of the leaf, giving it the appearance of a stingray.
• ‘Thailand Giant Strain’ is a mammoth selection of C. gigantea with blue-gray-green leaves up to 5 feet long and 4 feet wide on a plant over nine feet tall under ideal conditions. This species requires better drainage than C. esculenta.
• ‘Yellow Splash’ is a yellow and green variegated type heavily splashed with creamy yellow patterns.

Use elephant ears to add a bold, tropical look to the landscape in borders, mass plantings or in containers. These fabulous foliage plants add dramatic contrast with both the size and color of the leaves and their form.  They combine well with other tropical plants such as banana, castor bean, colorful caladiums, Chinese hibiscus, and mandevilla, and they also provide wonderful textural contrast with more typical temperate bedding plants, ferns, or ornamental grasses. Pair dark-leaved varieties with any white, yellow, or orange-flowering plant for vivid contrast.

The clumping varieties have an attractive vase shape so a single plant can provide an interesting focal point in the garden when planted in the midst of low-growing annuals such as petunias or begonias.

Add them to large aquatic containers in combination with papyrus and water lilies or keep them in individual containers to mix and match with other plants on a deck or patio.

Many types of elephant ears can be grown in partial shade, but the darker colored varieties are best grown in full sun. All need fertile, moist soil and nearly all are perfect at the edge of a pond. Most can be grown in a few inches of standing water, and can be added to water gardens as emergent plants (the roots in water and with the soil just covered with water, but the plants not submerged).

These tropical plants grow best in warm temperatures and high humidity. They may languish in Midwestern gardens until warm summer conditions begin, and they will also falter when temperatures drop below 50 °F for prolonged periods of time.

The plants continually produce new leaves throughout the growing season. The older leaves that gradually die off can be removed to keep the plants looking tidy. Be sure to consider the potential for the elephant ear to shade out smaller plants as they grow when you choose a planting location in the spring.

Propagating Elephant Ears

Although they can be grown from seed, to grow large elephant ears, start with a large bulb or rooted plant (many of the newer cultivars are only offered as tissue cultured plants that have not yet formed corms). It takes a few weeks for the first leaves to emerge from bulbs.

These frost-tender perennial plants are best started indoors, potting up the bulb in March, placing the top of the bulb close to the soil surface, and keeping it in a warm location until it is planted outside when the weather warms up, usually in late May or early June.