Caladiums require a warm, moist soil, Mary, so some North Carolina gardeners prefer to start them indoors to get a jump on the season. If you're one of those, plant them in moist peat moss or potting soil in a container such as a shallow tray or flower pot. Barely cover the tubers with soil and place the container in a warm room with bright light. You should start them indoors approximately four weeks before planting outdoors. Good luck!
Douglas's hints are correct....but WARM room is the key here. Caladiums like summertime soil before they sprout vigorously.
Thanks for help was not sure how deep to start or when.
You're welcome, Mary. Good luck with your caladiums.