Soil Preparation and Planting
Best grown in fertile, humusy, organically rich, medium to wet soils in part shade or filtered sun. In general, green types can take higher light levels; dark-leaved ones need shade. Once nighttime temperatures are consistently 50-60° F, plant each bulb 6-8" deep and 2-4 feet apart. Water generously.
Fertilize Colocasia every three weeks during fall and winter. Use a liquid plant food with a balanced N-P-K ratio such as 10-10-10 or 20-20-20, diluted to half the strength recommended on the label. Water the fertilizer deeply into the soil immediately after application.
Elephant ears are high water plants. Water as needed to keep the soil consistently moist, and don't allow the soil to become dry. Colocasia likes wet soil and is even appropriate for planting next to a pond, or in water up to 6 inches deep. Check the soil often if the bulbs are planted in sunlight.
Fall Care and Storage
Dig Colocasia bulbs after the first frost in autumn if you live in a climate with cold winters. Cut the foliage down to 2 to 4 inches before cutting. Allow the bulbs to dry for a day, and then place the bulbs in a box of wood shavings or peat moss. Store the box where the temperatures don't drop below 45°F.