Taro (Colocasia esculenta) is often grown in the United States as an ornamental plant for its large elephant ear leaves. But in Hawaii, where the tuber is a staple in the Hawaiian diet, taro is mashed into poi and used for other foods, such as the potato-like taro chips. Never eat taro raw. Uncooked, it is toxic. Taro comes in both upland and wetland varieties. If growing the wetland type, you'll either need access to a boggy area or to a modified growing system. Home gardeners without a natural wetlands area create their own pocket-ponds with buckets. Grow potted wetland taro immersed in buckets to provide the plants with the flooded conditions they crave. Taro thrives as a perennial in U.S. Department of Agriculture plant hardiness zones 8 to 11.
Poke holes along the side and bottom of your smaller container to make room for the root system. Use a drill, nails, screwdriver, knife -- whatever works easiest and most safely for you -- to make a dozen or so 1/8-inch size holes.
Fill the smaller container with potting soil to which you've added 1 tablespoon of fertilizer and 1 cup limestone for every 1 gallon of soil. Leave 2 or 3 inches clearance between the soil line and the rim of the container.
Plant one taro corm in the center of the container, at a depth of 3 inches. Cover the surface of the soil with pebbles to reduce soil erosion after immersion.
Set the smaller container into the larger bucket.
Fill the larger bucket with tap water or nutrient-rich pond water, if available, until there is at least 3 inches of water above the soil line of the taro plant.
Poke 6 to 8 1/8-inch sized holes around the perimeter of the bucket, 2 inches above the water line. These overflow holes allow for excess rainwater or for water replenishment without toppling the smaller taro container.
Place taro buckets in part shade or full sun.
Add water as needed during times of low rainfall, making sure the taro plant pot is always submerged in at least 3 inches of water.
Fertilize weekly once the leaves emerge. Lift the taro pot from the bucket, remove some of the pebbles and sprinkle 1 tablespoon of a premixed 10-20-20 fertilizer on the soil. Replace gravel and lower the taro plant pot back into the bucket.
Withhold fertilizer once the taro plants are about 6 months old. While ornamental taro gardeners can continue fertilizing to encourage healthy, large leaves, those who grow taro for food should stop feeding taro at this stage. Halting the plant food helps ensure that all the plant's energy goes into the tuber, rather than the leaves.
Harvest tubers at 6 to 9 months or when the green leaves begin to yellow and die back.