I thought I'd toss this out for anyone interested. If no response in a few days I will bump it down. Tho I have a yard to garden in, it's interesting to see the various ways people adapt to their environment and still garden. This article is about various roof-gardening enterprises. barb
More companies create tools for rooftop gardening
TRENTON, Mich. ---- Using heat from a forge that turns orange-hot metal into everything from car parts to hand tools, a Michigan manufacturer is developing an energy-efficient way to warm a year-round greenhouse on the company's roof.
....snip....Sky Vegetables Inc.[ http://www.skyvegetables.com/about.html ] aims to build hydroponic farms on roofs in New York, Washington, D.C., and the Boston and San Francisco areas to make more fresh produce available in cities.
Another company based near Chicago, GreenGrid Roofs,[ http://www.greengridroofs.com/ ] sells a modular system of plastic bins that make it easier to install rooftop beds.
Here is a link that might be useful: More companies create tools for rooftop gardening