IN most ways, the Barthelmes Manufacturing Company is a typical sheet metal fabricator. Five days a week, machines here stamp out thousands of computer cases, electrical patch panels and other items for companies like United Technologies.
Yet a growing part of the company's business is being devoted to something decidedly unindustrial: edible walls -- metal panels filled with soil and seeds and hung vertically.
They may sound like a piece of Willie Wonka's chocolate factory. In fact, they are the latest development in green roof technology. Like green roofs, edible walls include a thick layer of vegetation on the outside of buildings to provide insulation and reduce heating and electricity costs.
But unlike green roofs -- and their vertical cousins, green walls -- edible walls also produce fruit, vegetables and herbs in far less space than typical gardens. That's why advocates of urban farming have embraced them as a way to lower food costs, increase nutritional quality and cut fuel consumption and carbon emissions by using fewer delivery trucks.