The Incredible Edible Wall

Reposted in full from 12 Degrees of Freedom [and New York Times], 19 November 2009

'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.

“The traditional metal fabrication industry is shrinking, and green is an emerging area,” said Larry Lehning, the chief executive at Barthelmes, whose sales of green products have doubled this year and make up 15 percent of the company’s revenue. Edible walls — descendants of espalier, or trees grown against walls that were popular during the Middle Ages in Europe — are just one small attempt to grow food in cities. For instance, Valcent Products builds greenhouses filled with hundreds of trays of hydroponic vegetables stacked on conveyor belts. Sky Vegetables hopes to build commercial farms on the flat roofs of hospitals, schools and food banks.

Dickson D. Despommier, the director of the Vertical Farm Project at Columbia University, envisions entire skyscrapers turned into indoor farms capable of growing 100 different crops.
All of these solutions, though, require large investments and considerable technology. Edible walls, by contrast, can be built for a fraction of the cost, do not need computers or greenhouses and require far less maintenance.

The leader in this niche area is Green Living Technologies, another company in Rochester that has built edible walls here, in New York City, Los Angeles, Detroit and elsewhere.

“Instead of bringing food to the city, we’re bringing the whole farm,” said George Irwin, the chief executive and founder of the company. “What we’re implementing is back to basics.”

The idea for the edible wall, which is often portable and hung from a structural wall, was inspired by Mr. Irwin’s young son and daughter about five years ago. Mr. Irwin, who was installing green roofs and green walls, was asked by his children if they could plant some lettuce seeds in a wall. Not expecting much, Mr. Irwin plopped the seeds into the soil in a panel that he was using for a sloped green roof. A few days later, they sprouted.

Mr. Irwin saw the potential for these vertical planters in cities where space is tight and food costs high. They can be hung in backyards, parking lots and other spots. He has sold them mostly to homeowners and schools, but he hopes to persuade restaurants and supermarkets to buy them so customers can pick their own food.

Uninterested in being a manufacturer, Mr. Irwin has contracted with Barthelmes and other companies for 2-foot-by-2-foot stainless steel and aluminum panels and other products.
The panels have intersecting slats inside that create 24 cells for seeds to be planted. The slats have long holes in them so roots can migrate between the cells, strengthening the soil and plants.

Mr. Irwin, who has an online column as the Green Wall editor, holds two-day seminars where landscape designers pay $800 to learn how to install products made by Green Living Technologies. One of the nearly 500 resellers is Kari Elwell Katzander, a landscape designer in New York City. She comes up with designs for her customers and then calls Plant Connection, another of Mr. Irwin’s partners, which recommends plants to grow and then cultivates them for two to five months at its nursery on Long Island.

In early November, Ms. Katzander installed three panels, each four inches deep, for Brad Zizmor, who has a backyard deck at his first-floor apartment in Manhattan.

Ms. Katzander and Plant Connection decided on 10 plants, including strawberries, lettuce, chives, oregano, parsley, rosemary and thyme. The panels, which weigh about 50 pounds each when filled, were hung on a wooden wall that surrounds the deck.

To irrigate the plants, a quarter-inch hose with tiny holes was draped across the top of the panels and attached to a larger hose. Ms. Katzander figured out how often to feed the plants to avoid runoff and to ensure that the plants would not be too dry or wet.

“What’s nice is you can be surrounded by the food you’re eating,” Mr. Zizmor said.

Mr. Zizmor is considering whether to keep several panels cultivating on Long Island so he can swap them out each season.

At about $125 a square foot, or $500 per planted panel, plus more for design, delivery and maintenance, edible walls do not make sense for every home, or even cities where there is open land.

Still, Mr. Irwin has shown that edible walls can work on a larger scale. At four locations in the Skid Row area of Los Angeles, there are walls with more than 4,000 plants growing: tomatoes, cucumbers, bell peppers, spinach, leeks, even baby watermelon. At one location, a homeless shelter, residents tend to a six-foot-high, 30-foot-long wall, eating some food they harvest and selling the rest.

The project, urban farming advocates say, is just the start of something larger.

“We have 30 miles of rooftop in New York City and maybe 3,000 miles of walls,” said Paul Mankiewicz, the executive director of the Gaia Institute in New York. “It’s basically about maximizing the productivity per square foot.”'