National Geographic News

Mark J. Miller

for National Geographic

Published April 29, 2014

This story is part of National Geographic‘s special eight-month “Future of Food” series.

For most urban dwellers, visiting a working farm requires a journey into the countryside. But in a growing number of world capitals, a farm is just a short elevator ride away—on the roof.

In Singapore, Amsterdam, Hong Kong, Tokyo, and Montreal as well as several U.S. cities, farms have been built atop multistory buildings.

"Five years ago, there were virtually no rooftop farms," Steven Peck, founder and president of Green Roofs for Healthy Cities, told National Geographic. "Now they are starting to appear across the globe."

Peck says that as fossil fuels become more expensive and the number of urban dwellers continues to rise, urban farming will help feed the population without increasing the cost and pollution of food transport.

Rooftop farming was born out of the green-roof movement, in which building owners partially or completely cover roofs with vegetation atop special waterproof membranes. Green roofs use plants and flowers to provide insulation, create a habitat for local wildlife, help control runoff, put more oxygen into the atmosphere—and provide a welcome, verdant break from urban drabness.

Rooftop farms take the green-roof concept a step further, with plots that provide fruits and vegetables for local residents and the chance for urban volunteers to become part-time farmers.

"There is nothing more rewarding than sitting down at the end of a good day of working with our hands, watching the sun set over a healthy, productive farm, and enjoying some freshly picked vegetables as a team," said Anastasia Cole Plakias, vice president and founding partner of Brooklyn Grange, the world's largest rooftop farm.

The grange covers 2.5 acres (one hectare) on two buildings in New York City. More than 50,000 pounds of organically cultivated produce are grown there annually, for sale to local restaurants and at the grange's own farm stand. Chicken coops and more than 30 beehives round out the urban farming experience.

Brooklyn Grange opened in 2010 after Ben Flanner, the grange's head farmer and president, spent a year developing a 6,000-square-foot (557-square-meter) pilot project. With the information from that experiment, he and his partners scaled up to 43,000 square feet (3,995 square meters).

"As we realized that we were able to grow quality food in this unique setting, we dove in and pursued the idea without hesitation," Flanner said. "Our hopes and expectations were to grow as much tasty produce as possible and figure out the scale necessary to make all of the production and finances work."

That spirit has helped the organization increase its employee base, product line, and revenue streams. Events are also held at the farm, and schoolchildren visit often.

Brooklyn Grange also provides a nice getaway for the residents of the buildings below. Each week the farm opens its doors for visits from the hundreds of tenants as well as employees. "Having a farm on a roof is not a normal thing, so the farms are definitely the topic of a lot of conversation, excitement, and questions amongst the neighbors," Flanner said.

Other cities are joining the rooftop-farm movement. Peck ranks Boston along with New York City as the nation's top locations for rooftop farming. Cole Plakias notes that Chicago has long been a leader in greening rooftops.

"Taking that green-roof model to the next level and growing food in deeper soil is a relatively new concept that we've largely pioneered," Cole Plakias said. "New York City has been incentivizing green roofs with grants and tax abatements, which is a very smart move for a city facing aging storm-water-management infrastructure."

Such legislation has been important to creating rooftop farms in other cities, Peck said, as well as to helping build another alternative agricultural movement: vertical farms. This relatively new concept centers on the idea of a many-storied greenhouse with different crops grown on different floors.

Vertical farms have already helped the U.S. government grow genetically modified plants in Texas to use in vaccines. They've also been used to help Japanese residents around Fukushima find ways to farm again, since much of their land was lost to farming after it was irradiated in the wake of the 2011 tsunami.

In Milwaukee, Will Allen, one of the nation's green-roof pioneers, has begun work on building a five-story vertical farm. Allen says it could serve as a model for farms that go as high as a hundred stories.

Joe Nasr, of the Centre for Studies in Food Security at Toronto's Ryerson University, who has been studying urban agriculture for decades, notes that the rise in rooftop farming isn't limited to commercial operations. "Rooftop farming and gardening has become extremely diverse, and in that sense a more 'normal' presence in cities," he said.

In Toronto, he added, rooftop gardens and farms now appear atop restaurants, hotels, supermarkets, senior housing, rental housing, condo towers, old industrial buildings, schools, university buildings, community centers, and office towers.

In Peck's view, rooftop farming "is still very much in its infancy. But it has a lot of promise to provide jobs and healthy food in cities."

Follow Mark J. Miller on Twitter.

15 comments
John Howard
John Howard

Ha! Financially and Environmentally dishonest! The costs (both in carbon emissions and dollars) involved manufacturing and shipping to cities the light-weight soils (actually fake soil-less media) won't be paid back for a hundred years! This is just good ol' fashioned subsidy farming!

Enah Mae Dayanan Taran
Enah Mae Dayanan Taran

it's very innovative. hopefully people in our country, especially those who have the resources will do something like this in our urban areas and owners of condominiums will initiate such practices...

godfrey maele
godfrey maele

This is positive imagination in action. Thank you for the article. I pray that this information gets to many people. At least i will do my best to trumpet it to all my friends and acquintances.

Antonio Sagansay
Antonio Sagansay

this is a great study to make a good a healthy vegetables for any one ...i love it very much

Unity Addison
Unity Addison

This is such a good idea. It is providing local produce for citizens and it is helping to lower CO2 emissions. Great job guys!

wayne roberts
wayne roberts

Great to see this article in such a respected publication: I'll shout it out from the rooftops! I think one (of many) thing we have to keep in mind is that this is only sustainable as city policy for typical situations (not just uber-pioneers like Ben) if we integrate green roofs as green infrastructure and social infrastructure that produces "ecosystem services" and receives some support fro the city to thank the sponsors for  helping everyone -- not just through food but by absorbing rainfall and keeping it out of sewers, cooling the city on a hot day, providing services that allow more people to meet and exercise, and so on -- all of which produce savings for taxpayers in return. I outline my strategy for that in my book, Food for City Building. Thanks again, Wayne 

Sopavanh Rassapong
Sopavanh Rassapong

I think it is a great idea to use roof for farming. However, I wonder if it will not affect the strength of the building or not. Can water or mineral in soil can undermine the concrete or not? 

Jackie Figue
Jackie Figue

Idea maravillosa para aprovechar tanto espacio inútil y a la vez una excelente forma de autosustentar una comunidad. La Hidroponia es muy efectiva en estos casos. Ojalá se replicara a nivel mundial.

Taylor Auffarth
Taylor Auffarth

Obviously we have all read or heard about this but it really is a neat alternative to bring farm fresh produce closer to cities. 

Lauren Mandel
Lauren Mandel

Brooklyn Grange is certainly a pioneer in the burgeoning rooftop farming industry.  For detailed information about Brooklyn Grange and other North American rooftop farms and gardens check out "EAT UP | the inside scoop on rooftop agriculture" (New Society Publishers, 2013), the first full-length book about rooftop food production.

eatupag.com 

Walter Matera
Walter Matera

Rooftop farming can work in climates with ample rainfall but the idea of a skyscraper farm is silly.  It would require massive irrigation to properly water more than a few stories.  While the programs cited above can work well the skyscraper farm is another New Urbanist fantasy . . . along with the idea that children can be healthily raised in concrete canyons.

Chase Emmons
Chase Emmons

@John Howard Hi John.  Just saw this comment.  We work with Skyland for our soil, which is made up of repurposed mushroom compost and various types of lightweight but highly porous stone.  While it is clearly more energy intensive to initially build the farm than simply picking a parcel of land outside the city, the benefits are myriad and definitely factor into what you might be considering an EROEI.  Just a couple of examples of what you might not have thought of: energy saving in HVAC for the building below.  Energy savings with the 1 million gallons of stormwater we stop from entering the system, and a bit of mitigation for the local urban heat island effect.  Again, those are just a small sample of the benefits.  As for our financials, I'm not sure how you can comment on them as you do not have access.  Though I will say that our investors are already receiving dividends even with our continual expansion.

Marina Milenov
Marina Milenov

@Sopavanh Rassapong  "Rooftop farming was born out of the green-roof movement, in which building owners partially or completely cover roofs with vegetation atop special waterproof membranes. " 4th paragraph

Lauren Mandel
Lauren Mandel

Hi Sopavanh,

Good questions!  Buildings on which green roofs and rooftop farms are built are first evaluated by a structural engineer to make sure they can support the anticipated weight.  If the building checks out, then the green roof or rooftop farm is designed to protect the roof's waterproofing layer (the synthetic membrane above the concrete or steel roof deck that keeps the building dry).  If properly designed and built, there's no need to worry about damage to the waterproofing layer, roof deck or building.

Lauren       

Deddy Hadinata
Deddy Hadinata

@Walter Matera  

It can works just fine. Yes, it would be more expensive compare to the traditional farming. But consider the lower carbon footprint: Traditional farming leaves higher footprint due to the land conversion and transportation.


With precision fertigation, water can be used more efficiently. By choosing the right crop, right varieties, with better conversion of water, fertilizers and sunlight into dry matter, further efficiency can be achieved.


Of course hi-rise farming is more challenging due to the extreme condition (lower humidity, higher wind, higher solar radiation). But, it can be solved with some modest protection with polyethylene covering for example.


Another problem is the additional load to the building.

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