A large, showy, marginal aquatic plant with heart-shaped, dark green leaves, elephant's ears can reach 5 feet tall and are often used as a summer annual or container plant in the Chicago area. In tropical areas around the world, the starchy tubers are cooked to make poi, a dietary staple. The leaves, cooked to rid them calcium oxalate crystals, are used as greens. Grown for its eye-catching foliage, it prefers partial shade and humusy, moist or wet, slightly acidic soil. Taro can be grown in the ground or in a large aquatic container. Store dormant tubers in a dry, frost-free location.