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This article will help with growing: https://www.gardeningknowhow.com/ornamental/bulbs/elephant-ear/growing-elephant-ear-plants.htm
Leaf curling can be caused by numerous things, including too little or too much water. If yours are in full sun, it could be that the plants are curling up to try to conserve water; therefore, additional water may be needed. Check the soil around the plants to see how dry it is and water as needed to keep the plants hydrated.