Colocasia gigantea 'Thailand Giant Strain'
Common Name: giant elephant's ear
Type: Herbaceous perennial
Family: Araceae
Zone: 8 to 10
Height: 6.00 to 10.00 feet
Spread: 6.00 to 10.00 feet
Bloom Time: April to June
Bloom Description: Yellowish-white
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Medium
Flower: Showy
Leaf: Evergreen
Other: Winter Interest
Tolerate: Rabbit, Deer, Wet Soil

Culture

Best grown in fertile, organically rich, continuously moist to boggy soils in full sun to part shade. Soils must not be allowed to dry out. Plants grow best in areas with high summer heat and high humidity. Plants produce prodigious amounts of growth and appreciate regular fertilization during the growing season. Site plants in locations protected from strong winds (giant ornamental leaves lose much of their ornamental quality if torn apart by strong winds). Tubers may be left in the ground year round in USDA Zones 7b-10. In St. Louis, however, tubers should be planted in the ground in mid-spring (after April 20), dug up in fall after first frost and then overwintered in a cool dry location (set in dry peat or wood shavings) where temperatures do not dip below 45 degrees F. in somewhat the same manner as is done for cannas. If grown in large containers, the containers should be brought indoors to a frost free basement for overwintering (best to leave the tuber in the container rather than remove it). Plants may be propagated by dividing large tubers.

Noteworthy Characteristics

Colocasia gigantea, commonly called elephant’s ear, is a large, stemless, tuberous, frost-tender perennial of the arum family which typically grows to 4-7’ tall and as wide and features huge, heart-shaped to arrowhead-shaped, conspicuously-veined, downward-pointing, peltate, dull green to gray green leaves (to 2-4’ long) on stout, succulent stems. As the common name suggests, each leaf purportedly resembles the ear of an elephant. It is native to valley forests in China and southeast Asia. For gardeners, it is primarily grown as a foliage plant. Calla lily-like flowers with yellowish-white spathes and spadixes are infrequently produced and often hidden by the foliage when they do bloom. In its native habitat, edible leaf stems are sometimes eaten as a vegetable or used as food for hogs. Foliage is evergreen in frost free climates.

Genus name comes from the Greek word kolokasia used for the root of Nelumbo nucifera.

Specific epithet refers to the giant size of this plant.

‘Thailand Giant Strain’ is a cultivar that is larger than the straight species, producing leaves that are 4-6’ long and 3-5’ wide on plants which soar to as much as 10’ tall (infrequently taller). Seeds for this massive strain were collected in the wild in Thailand in 2003 by the Research Manager of Plant Delights Nursery of Raleigh, North Carolina.

Problems

No serious insect or disease problems. Spider mites may be present in dry conditions.

Garden Uses

Lends a bold and dramatic tropical look to the landscape. Should be sited in areas where its massive growth can be accommodated. Excellent as a specimen or in small groups in marshy pond margins or in moist areas around patios or in borders. May be grown in large containers (smaller resulting plant size), which are overwintered indoors.