In order for the crops to grow you have to have someone be within a certain distance, believe just in the chunk, of them. It is the same with cows and other animals. If noone is around nothing grows. Almost philosophical if you think about it. If noone is around to see your crops grow, do they really grow? Guess the answer is no.
no my crops aren't growing either and I'm on the same chunk as them just a layer above them