Green roof designer Lauren Mandel of Mt. Airy is the author of the just-published book, “Eat Up: The Inside Scoop on Rooftop Agriculture” (New Society Publishers, 2013). Lauren works at the green roof firm Roofmeadow, also in Mt. Airy.

by Lou Mancinelli

“Eat Up: The Inside Scoop on Rooftop Agriculture” (New Society Publishers, 2013) is a new book from author and green roof designer Lauren Mandel, who was raised in Mt. Airy and now works at the green roof firm Roofmeadow, also in Mt. Airy, as Project Manager and Rooftop Agriculture Specialist.

The book explores the practices and practicality of rooftop gardening through case studies, interviews and other sources from three different perspectives: home rooftop gardening, commercial rooftop farming at places like restaurants, and lastly how it applies to those in the design industry like city planners and architects.

“People are starting to rethink our food system,” said Mandel who started the book four years ago while studying for her master’s degree in landscape architecture from the University of Pennsylvania, which she earned in 2010. “Not just city planners but everyday people.”

In the past few years the popularity of rooftop agriculture has risen so much that the first draft Mandel completed in 2009 evolved into a much more extensive work by its fifth and final draft.

A New York Times article she read while in school first piqued her interest in the subject. She started “thinking about whether or not it was actually viable.” Since then rooftop gardens have grown from boutique appeal to generating widespread interest. In the book Mandel examines what cities in North America have a burgeoning rooftop agriculture scene or have the potential to develop one. Some historians believe that rooftop agriculture’s history dates back to 600 BCE Iraq, where produce and even fish were grown on the Hanging Gardens of Babylon’s terraced roofs.

In 2010, the Eagle Street Rooftop Farm in Brooklyn became the first community supported rooftop agriculture program in the country. This spring workers in Boston broke ground on construction of the Higher Ground Farm on the roof of the Boston Design Center. When completed, the 55,000 square foot space will be the second largest open-air roof farm in the world, second to the 2.5 acre organic farm Brooklyn Grange, which also opened in 2010.

Mandel identifies New York City, Philadelphia, Chicago, Portland (Oregon), San Francisco, Toronto, Montreal and Vancouver as cities poised to lead the way in the rooftop agriculture trend. They are cities with attributes favorable for rooftop farms and gardens like high building density, adequate building stock and strong civic groups.

It is expected that 70 percent of the world population will live in cities by 2050, according to the Population Reference Bureau. As more people live in cities, the need for fresh fruits and vegetables will increase. The rising costs of fuel will also be reflected in the cost of produce.

Will city residents prefer to buy vegetables grown on the roof of their local market or coop? Mandel says there’s even sex appeal to rooftop farms. There is the chance to create a sustainable image.

Restaurants with rooftop agriculture will truly be able to boast about “hyperlocal, hyperfresh” food. Even some schools are considering raising their own rooftop vegetables. For example, Roofmeadow has partnered with the Lower Moyamensing Civic Association to develop a master greening plan to construct a 5.5-acre rooftop farm at the South Philadelphia High School. A campaign to raise $26,300 for the farm that would include educational programming and produce sales concludes June 9.

Mandel, 30, a 2005 Skidmore College environmental science graduate, attributes part of the growing popularity of rooftop agriculture to the social media campaigns launched by the farms’ staff, which she said are often made up of late 20-something and early 30s entrepreneurs. Their efforts may usher rooftop gardening into the mainstream.

Philadelphia already has one of the most progressive stormwater management codes in the country. Green roofs are now required by code in large scale projects. Might rooftop farms be part of that code in the future?

Because the idea is relatively new, Mandel said it’s difficult to estimate costs. The cheapest system is about $10 per square foot for a soil-based system planted in rows, known as a row farm. Cost depends on design. Would the farming be done in containers or raised beds? On the other end, a high quality rooftop hydroponic greenhouse could cost up to $70 a square foot. Also, a roof might be required to be strengthened before it is ready for urban farming.

Mandel, a 2001 Germantown Academy graduate, is launching her book through a series of roof-to-table exhibitions in nine cities throughout North America. She celebrated her local release April 25 at Good Karma Cafe in Center City. The exhibition will remain there (at 928 Pine St.) until June 30 when Mandel travels with it to Chicago.

“Rooftop agriculture is hot right now,” said Mandel. “Green roofs are important for aesthetics, but rooftop agriculture is also important for human health.”

“Eat Up” is available online at Amazon and Barnes and Noble. For more information about Mandel and rooftop agriculture, visit her blog at eatupag.wordpress.com.