By Blair Thomas
These vegetable gardens are reaching great heights. At Chicago O’Hare International Airport, 26 aeroponic grow towers were installed between terminals 2 and 3 last year.
Aeroponic refers to a method of hydroponic, or vertical gardening, in which seeds are planted in small cubes of nutrient-dense spun volcanic rock, which holds in water and naturally biodegrades. Once plants grow to a certain size, they are transferred to the horizontal aeroponic towers. There, the plant roots are sprayed with a fine mist of water and a mineral nutrient solution for 15 minutes every 30 minutes.
The mist becomes highly aerated, which provides the plant roots with a high level of oxygen. These oxygen levels combined with adequate light and ventilation are a good mix and help produce as much vegetation as traditional soil gardening.
The water is recycled through the towers – which are 8 feet tall with a 30-inch diameter base – so no water evaporates or is wasted. This gardening method also utilizes space well. These gardens are cultivated year round, require no weed pulling, take up less space and produce more per unit than a traditional garden.
At O’Hare, the towers grow sweet basil, purple basil, dill, parsley, chives, lettuce, habanero peppers, thyme, oregano and green beans. Many of these crops are harvested and served at airport restaurants including Wicker Park Seafood & Sushi, Tortas Frontera by Rick Bayless and the Wolfgang Puck Cafe.
Here’s a video on another vertical garden operation in the Chicago area, FarmedHere LLC: