can you live in a house full of flowers without food?
Unless the plant's leaves or roots can be eaten by the fish, it is advisable to feed the fish no matter the circumstance.the plants won't give all the nutritional values the fish need to get to grow and be healthy. they may have lots of vitamins to eat, but what of the much needed proteins and carbohydrates? 
The answer remains NO, they can live but won't live up to their full potential without proper feeding.
Oh the other thing, for those who may bump into this question, here is a link for you to read- http://homeaquaria.com/5-reasons-why-artificial-plants-are-better-than-live-plants/