Green walls and roof gardens have become extremely fashionable. One New York supermarket is taking the idea two steps further.

Rather than just plant any greenery on the roof, Whole Foods is partnering with Gotham Greens to construct an 1,860 square metre greenhouse on its roof.

As well as the usual benefits of a green roof and of providing food, the project will reduce foe food miles of the produce to mere "food footsteps".