Elephant ears or Colocasia are native to tropical Asia and India. Their bulbs are used to make a food known as poi and are grown in gardens for their large attractive foliage, which look like the ears of an elephant. Elephant ears are used in beds and borders, and in moist areas around ponds. There are dozens of cultivars available, and their colors range from chartreuse to black. Some species can grow to 84 inches.
Start the bulbs indoors in containers of potting soil 8 to 10 weeks before planting them outdoors in the late spring. Plant the bulbs directly in the ground in the spring In zones 7 through 10.
Plant the bulbs with their roots facing down. Dig a hole 3 to 4 inches larger than the diameter of the bulb. The top of the bulb should be 2 to 3 inches below the soil. Plant the bulbs 12 to 18 inches apart.
Cover the bulb with 2 to 3 inches of the organic matter until the organic matter is even with the soil. Organic planting mixes available at garden supply stores can be used if the soil contans a lot of clay. Elephant ears need rich, moist soil.
Water elephant ears frequently if they are planted in full sun. Elephant ears do better in the shade but can tolerate sun with frequent watering. Keep them evenly moist and never allow them to dry out. Add a 2- to 3-inch layer of mulch after planting to help retain moisture.
Apply a 20-20-20 time-release fertilizer once a month because elephant ears are heavy feeders. Use the fertilizer all season to help the plant produce large leaves.