Roof top gardens in NYC

I read recently that New York city is encouraging roof top gardens even on roofs of corporate buildings. Maybe this is a sign of the economy. Not a bad thing, I would say. Employees probably don't get raises anymore. Now they can at least get the vegetables! I have shopped for fruits and vegetables in NYC and they are expensive. This is a great way to cut costs somewhat, especially if you are a die-hard vegetarian like I am. I go nuts over fresh fruits and vegetables. I need to buy them every week to cook my meals.