As the temperature on an October afternoon began to dip, Sophia Leonora-Mendelsohn walked briskly outside JetBlue’s departures lobby at Kennedy International Airport and ran her hand across the top of a crate of kale seedlings just beginning to sprout.
The season’s first frost seemed only days, if not hours, away, and she wore a look of obvious concern. All her work — 3,000 crates, lined up and stuffed with herb and vegetable plants — would need to be removed before the plants perished in the cold.
It took three years for Ms. Leonora-Mendelsohn, as JetBlue’s head of sustainability, to clear the bureaucratic hurdles for a farm to be positioned on the airport grounds, just outside Terminal 5, where half a football field of space once sat as an empty eyesore to travelers zipping by on moving walkways.
Now, this rooftop was blooming. It had adopted a color that is becoming more familiar to contemporary airports: green.
JetBlue’s latest project — replete with 26 varieties of plants, including potatoes, kale, dill and oregano — is perhaps the most extreme illustration of airports’ efforts to infuse natural elements into sites that have been more commonly associated with asphalt, canned air, loud machinery and noxious emissions.
But in recent years, airports in Vancouver, British Columbia; Mumbai, India; and Birmingham, Ala., among others, have erected enormous indoor “living” walls composed of plants and greenery.
In Chicago, O’Hare Airport features a soilless aeroponic garden springing up vertically from the mezzanine level of Terminal 3. Schiphol Airport in Amsterdam includes an indoor “mixed nature” park, with ivy-covered chairs and piped-in bird sounds. And Changi Airport, in Singapore, offers weary travelers rooftop cactus and sunflower gardens, and a two-story butterfly house.
These earthen themes are becoming more commonplace, and more creative, with JetBlue’s new terminal farm being the latest example.
“We live in concrete jungles,” Ms. Leonora-Mendelsohn said. “People want access to that green.”
David Robbins, the Chicago Department of Aviation’s project administrator, said in a telephone interview that O’Hare’s push for more greenery began as part of an $8.7 billion modernization program begun in 2001. The airport now has its own living wall, 12 green roofs, the first major airport bee farm in the country, and the 900-square-foot garden, which opened in 2011, appropriately abutting a yoga studio.
“The garden provides a place of calm,” Mr. Robbins said. “It’s a place of refuge for people to relax and soak up the greenery. It’s a very pleasing environment.”
The effort is not without its costs. Building these green spaces can often come at the sacrifice of additional commercial opportunities, in places where real estate is precious. O’Hare’s garden employs a farmer to manage the crops, and what is produced is hardly enough to trim passenger food costs.
But Mr. Robbins called the strategy a philosophical move, even if it is largely symbolic, showing customers that Chicago’s airports are serious about their sustainability initiatives.
“There are opportunity costs when you talk about other options,” he said. “But the real opportunity is to make a statement about the environment through this.”
JetBlue’s Terminal 5 farm, which is run in conjunction with GrowNYC, a nonprofit focused on improving New York’s environment, is open only to select tour groups and airline staff members. On a recent afternoon, several crew members milled about the crescent-shaped space as they waited for a shuttle to arrive. One man beamed as he boarded the bus carrying a handful of small, round, blue potatoes.
The chef at Bar Veloce, in Terminal 5, has been known to pick fresh vegetables for his restaurant, but for the time being JetBlue is not serving any of its crops to passengers. The produce is instead hauled off in trucks and distributed to food banks in Queens and Brooklyn.
What JetBlue receives in return, Ms. Leonora-Mendelsohn explained, is brand enrichment, by creating what she called “the world’s coolest terminal.”
“We don’t save money by growing our own vegetables,” Ms. Leonora-Mendelsohn said. “We enhance our brand by doing gutsy things like this.”
Henry Harteveldt, a travel industry analyst, said the success of JetBlue’s farm would almost surely be followed by other airports’ dreaming up novel ways to transform once-dull spaces into green spaces. This new green strategy is rapidly becoming part of the design process for airport architects and designers.
“Airports realize that if they green, it can curry favor with the community, build good will, and it makes them a more welcomed part of the community, beyond just the function they provide,” Mr. Harteveldt said.
Mr. Robbins said that airports had visions of finding new ways to transform their empty spaces, particularly the open land around runways and hangars.
Detroit’s airports, for instance, have started using some of their vacant property to grow and harvest crops for biofuel. Mr. Robbins said O’Hare had been looking at additional containerized agriculture.
“We talk about things like this,” he said. “We’re looking at other ways to expand on the idea of localized farming around and about airports.”
One objection raised by the Port Authority of New York and New Jersey to JetBlue’s farming plans was that it could attract birds, creating potential hazards to planes. The farm opted to grow only nonflowering plants. So wheat, which JetBlue envisioned could be used for beer production, had to be crossed off the list.
The airline estimates, however, that more than 80,000 gallons of annual rainwater could be diverted from sewer lines thanks to the soil in the crates, soil that came from composted food scraps from the terminal next door. Soon, JetBlue plans to add its own apiary, perhaps even a butterfly house, supplying other colors to its green palette.
“You cannot impress customers with a Santa Claus at the T.S.A. line anymore,” Ms. Leonora-Mendelsohn said. “They have higher expectations when they’re here.”