Hydroponics and the City

In the absence of large areas of arable land, the Big Apple has increasingly embraced urban rooftop, hydroponic and aeroponic gardening to produce farm-fresh produce for New Yorkers.

Report by CHRISTINE PAUL-BROWN Photography by SAM ROSS


Across the globe, a growing trend in cities is the increasing demand for locally grown produce. All too often, consumers complain that produce on offer is not sufficiently fresh after having been transported from often considerable distances away. With the ever-expanding popularity of hydroponic and rooftop gardening, however, even densely populated cities like New York, without large tracts of arable land and with inclement weather in the winter, can source their own fresh, local fruits and vegetables. In the face of global warming, drought, weather instability and runaway energy costs, hydroponic agriculture, with 10 times that of field-crop yield, makes increasing sense.

“Locally grown food plays an increasingly important role in our society nowadays,” said Michael Christian, CEO of American Hydroponics. Based in Humboldt County, California, the company has been a manufacturer of state-of-the art hydroponic systems since 1984.

“More and more consumers attach value to the origin of their food and how far it had to travel to get to them. They want it to be grown next door in an environmentally friendly manner. They want to know who grows it; they want a face with their produce.

“Our growing systems definitely help local growers to set up their business. Now they can harvest consistent quality, year-round uniform, pesticide-free produce and offer it at local markets. Because the food chain also is shorter, the produce reaches the consumer in pristine condition. Specialty buyers appreciate this and therefore pay higher prices for these products. Loyalty develops between growers and buyers through quality and consistency … all attributes of locally grown,” Mr Christian said.

André de Waal, chef and an owner of the haute André’s Restaurant in Newton, New Jersey, buys his hydroponic vegetables from a small rural greenhouse just 15 minutes away, saying that vegetables from California are more than three days old by the time they reach him.

“Given the choice between days-old produce grown in soil, and super-fresh hydroponic vegetables, I’d rather have the hydroponic,” Mr de Waal said.
“There is nothing quite like working with produce that is several hours old.”

Chef John Mooney samples some of the herbs grown on the rooftop of his Bell Book & Candle restaurant in New York.

Chef John Mooney samples some of the herbs grown on the rooftop of his Bell Book & Candle restaurant in New York.

Rooftop to table
Respected New York chef, John Mooney agrees, putting hydroponics on the menu at his Bell Book & Candle restaurant in trendy West Village, NY. Winner of the 2011 New York Rising Star Sustainability Chef Award, Chef Mooney runs a food program that revolves around local, organic, sustainable and overall responsible procurement. Menu cycles are seasonal and heavily influenced by production from the restaurant’s aeroponic rooftop tower garden. A form of hydroponics, aeroponics is a system that sprays a nutrient-rich mist at plant roots instead of submerging the roots into the solution. The result is quick yields, intensely flavoured vegetables and very little waste.

Having honed his hydroponic gardening skills at previous restaurants in Orlando and India, Chef Mooney sources the majority of his current restaurant’s ingredients from the 60 or so hydroponic towers on the building’s roof. He uses sustainably farmed proteins (preferably local), drawing on his entire pantry to create a considered, expressive menu that showcases the refined and innovative potential of American cuisine.

The most popular dishes on the menu at the Bell Book & Candle are the wild salmon with caramelised cauliflower and lime emulsion, the fried chicken, and the living leaf salads picked daily from the roof garden.

Chef Mooney, together with restaurateur partner, Mick O’Sullivan, grows an impressive variety of produce throughout the year. This includes: sage, chive, chervil, cilantro, dill, Genovese basil, opal basil, Italian and flat leaf parsley, spearmint, rosemary, four varieties of nasturtium, cheddar cauliflower, purple tomatillo, tomatillo, Japanese and kermit eggplant, two varieties of arugula, four varieties of cherry tomato, great white tomato, bibb lettuce, red oak leaf, red and green romaine, lolla rosa, frisee, green crisp, poblano pepper, and fennel.

“The garden came to fruition after Mick and I had a plantation in Orlando, Florida. We found it very hard to run a restaurant and farm. The labour was too much so we looked to find technology to help us,” Chef Mooney said.

“We found Tim Blank of Future Growing who invented the Tower Garden aeroponic system. His technology naturally translated into the urban farm we now have on the roof of Bell Book & Candle.

“I grow all my herbs, tomatoes, eggplant, watermelon, strawberries, tomatillos, zucchini, zucchini flowers, cucumbers, chili peppers, nasturtium, as well as many others and plenty of variety of each,” he said.

As customers enjoy their food at the restaurant, few realise that the herbs and vegetables on their plates have come from the rooftop garden just six floors above them, with all the freshly-picked produce lowered by a pulley system straight into the kitchen.

“We call it rooftop to table,” Chef Mooney said.

Growing up
A vertical garden system, the Tower Garden® system used at Bell Book & Candle is a state-of-the-art aeroponic growing system specially designed for growing on rooftops, patios, balconies, terraces or any relatively sunny place.

The basic Tower Garden unit has a 2.5′ x 2.5′ (0.76200m x 0.76200m) footprint, and uses modular stackable growing pots. With an 11-pot maximum configuration, the system allows for growing up to 44 plants per tower. Seeds for the Tower Garden are started in a natural rock fibre seeding cube. Following germination, the cubes are placed in full light for a week or two where they can develop into hardy seedlings ready to transplant into the Tower Garden.

Made from white, food-grade plastic, enhanced with UV protection, the Tower Garden has a 25-gallon (95L) reservoir at its base, which stores the Aeroponic Power-Gro ionic mineral nutrient solution. Inside the reservoir is a small, low wattage submersible pump. The pump draws the nutrient solution up through the centre of each pot all the way to the top of the Tower Garden. From there, the nutrient solution drips through a special device that evenly cascades the nutrient solution over the plant roots. On the journey down the tower, the nutrient solution feeds the plants’ roots and becomes highly oxygenated as gravity tumbles it back down to the reservoir.

This process is continually repeated, providing fresh oxygen, water and nutrients to the roots of the plants. Because of the design of the Tower Garden system, crops grow faster than they would in soil, and have to be harvested on a regular basis.

“Amazingly, it took just four days to transform the rooftop from plain black asphalt to a fully functioning rooftop hydroponic oasis,” Chef Mooney said.

“I don’t weigh my production as I’m not a retailer, but the 2400-square foot (223m2) garden equates to about the same as a two-acre (0.81ha) conventional farm.”

“I think in the next 10 years [growing like this] will be so common. Recently, a friend of mine who owns a big record label in Chicago put 10 towers on his personal home in Chicago. There’s another sustainable seafood restaurant I do work for in Washington DC, and we have 20 towers coming for them in two weeks. At the Hearst Tower, they also have some of this technology there,” he said.

New York’s first ‘green’ skyscraper, the Hearst Tower was opened in 2006 and features a number of environmental considerations, including hydroponics, built into the plan. With its efficient use of resources, abundant natural daylight and fresh air, and modern technologies, this 856,000-square-foot (7952m2) building designed by Foster + Partners, received an LEED Gold rating for its core, shell and interiors, and is designed to consume 25% less energy than most Manhattan towers.

Gotham Greens
An urban farm on a warehouse rooftop in Brooklyn’s Greenpoint neighbourhood, Gotham Greens was founded in 2008 when Viraj Puri and Eric Haley had a vision for a local farm that would offer New York chefs and retailers the freshest and highest quality vegetables and herbs year-round, at competitive prices. In 2009, Jennifer Nelkin, a nationally renowned greenhouse expert, joined Gotham Greens as a partner to head all greenhouse operations.

“New Yorkers are increasingly demanding fresher, more nutritious food that is grown closer to home using more sustainable methods. Cities, particularly New York City, have a dearth of arable land. Hydroponics is extremely modular, lightweight, efficient and productive form of farming that lends itself well to an urban environment, particularly rooftops,” Mr Puri said.

“Hydroponic yields can be 10 to 20 times more productive per unit compared to conventional farming. As a result, we decided to build the nation’s first commercial-scale hydroponic rooftop greenhouse. At Gotham Greens we produce over 120 tons of leafy greens and herbs each year from 15,000 square feet (1393.5m2) of greenhouse and grow year round, 365 days a year.”

The fully enclosed, sterile greenhouses minimise pest and disease risk and are designed to give Gotham Greens’s expert growers complete control of the growing environment— light, temperature, humidity, CO2, nutrition—to ensure unmatched product quality.

The fully enclosed, sterile greenhouses
minimise pest and disease risk and are designed to give Gotham Greens’s expert growers complete control of the growing environment—
light, temperature, humidity, CO2, nutrition—to
ensure unmatched product quality.

At Gotham Greens, 25 employees propagate, hand-pick and hand-pack the produce; on the rooftop, a weather station monitors wind, rain, temperature, humidity, carbon dioxide and light intensity.

“We use nutrient film technique to grow leafy greens and herbs, including Boston lettuce, red and green leaf, oak leaf, lolla rossa, arugula and basil,” Mr Puri said.
“Our greenhouse has been designed to give our expert growers complete control of the growing environment—light, temperature, humidity, CO2, nutrition— which ensures unmatched product quality. Our fully enclosed, sterile greenhouses minimise pest and disease risk. Our crops are protected against inclement weather and extreme weather events ensuring reliable and consistent yields. Sophisticated computer control systems manage heating, cooling, irrigation and plant nutrition.”

Ms Nelkin, who can run the operation from at any location on the globe, can monitor electronic data displayed at the central computer on the rooftop via her smartphone.

“We create our nutrient recipes from scratch, and there is a different recipe for each plant,” said Ms Nelkin.

She added that flavour comes from a variety of compounds that include sugars and essential oils.

“If it’s picked ripe, the flavour will be there as well.”

Jennifer Nelkin and Viraj Puri first met at the New York Sun Works (a non-profit organisation) where they helped develop the Science Barge, a prototype hydroponic, sustainable urban farm and environmental education centre built on top of a barge moored on the Hudson River.

A major challenge the founders of Gotham Greens encountered in establishing their operations was that no precedent had at that time been set for a commercial-scale rooftop greenhouse farm.

“As a result we were venturing into uncharted territory. Some challenges included: logistic hurdles of rooftop construction as well as regulatory hurdles to get all the permits and approvals,” Mr Puri said.

“In addition, there was a challenge in finding a suitable location that could handle all the structural engineering requirements.”

Mr Puri says that Gotham Greens doesn’t sell its produce beyond a 15-mile range—the proximity reduces carbon emissions and also allows him to guarantee delivery to local customers. In the wake of Superstorm Sandy, the company was the only farm able to deliver fresh lettuce to local Whole Foods (WFM) stores.
As far as future plans go, Gotham Greens has two additional rooftop greenhouse farms in development—one located in Brooklyn and the other in Queens. Both will be operational in the spring of 2014.

Hydroponics and the city
Does Gotham Greens’ Viraj Puri see a future in large-scale urban rooftop farming?
“Perhaps, but I think it remains to be seen. We don’t necessarily see this as the future of farming. However, it can play a role for certain crops, particularly highly perishable crops, which are often grown far away from New York,” he said.

“There are many ways to farm responsibly and sustainably. This is one method that is suited to our unique geographic and economic context. At the moment, although rooftop farming is not an entirely proven concept, it is, however, a promising one.”

According to Viraj, one of the most important benefits hydroponics can offer includes the elimination of fertiliser and pesticide runoff, a leading cause of global water pollution.

“We are trying to demonstrate that sustainable, urban agriculture can be economically viable in the city,” said Jennifer Nelkin.

“The biggest challenge that we are facing right now is not the technology – we know the technology. It’s moving this technology into the city.”

About the author
Christine Paul is a Sydney-based journalist and regular contributor to PH&G with a special interest in the environment and sustainable technology (email: c.brown.paul@gmail.com). Sam Ross is a freelance photographer. His previous images appeared in PH&G in Sept/Oct 2012, Issue 126 (‘Soilless Culture in Shanghai’).  

PH&G April 2013 /Issue 130