@alisha-- Whether surgery is required or not depends on the size of the hernia. If it's a large one, then surgery has to be done, it will not heal on its own. For very small hernias, surgery is not necessary.
I apparently had a herniated umbilical cord as a baby and my mom said that she taped a quarter on my abdomen, right on top of where the hernia was and it healed quickly. I don't know if there is any scientific basis for this method, but applying some pressure on it consistently might actually help. It's a good idea to check with a pediatrician first though.