For centuries, American farmers have grown produce with soil, sunlight, and water.

A new farm, called Bowery, says it has found a much more efficient place to grow: inside a giant warehouse in Kearny, New Jersey.

Located about 15 miles outside New York City, Bowery estimates it has the capacity to grow 100 times more greens per square foot than the average industrial farm.

It's a vertical farm where everything grows indoors under LEDs that mimic natural sunlight. Instead of soil, crops sprout in nutrient-rich water beds on trays stacked from the floor to the ceiling. Currently, Bowery is testing over 80 different varieties of greens, including baby kale, mustard greens, and arugula.

Out of those 80, Bowery is selling six types for about the cost of most organic greens. Available at select Whole Foods in NYC starting the week of March 6, a five-ounce package of greens costs $3.99.

Cameras monitor Bowery greens on a growing tray inside its warehouse in Kearny, New Jersey. Bowery Bowery can sell its greens at a relatively affordable price because it automates a lot of traditional farm labor, co-founder Irving Fain tells Business Insider. Automated machines that connect to the growing beds are able to do things that humans normally would, like move and water the plants.

Fain says that the farm's operational costs stay low because of a proprietary piece of software, called FarmOS, that is constantly searching for ways to make the growing process more efficient. For instance, if Bowery finds a batch of romaine needs a different intensity of light or a cooler atmosphere, it can change the conditions in the warehouse using FarmOS.

Part of the farm's efficiency comes from the fact that the growing trays are stacked five to the ceiling and arranged in tight rows. The farm is also able to produce greens year-round.

Bowery Farm is ramping up for large-scale production (Fain would not disclose the farm's size or growing capacity). It's already working on its next farm in the tri-state area. In the future, Fain hopes to expand and launch more farms in other US cities and, eventually, internationally.

More people are moving to cities, and we're going to need a way to feed them, Fain says. The United Nations estimates that 66% of the world's population will live in urban areas by 2050.

"These are important problems that we're working on. These are problems that aren't unique to New York, let alone the US," Fain says. "We're going to see populations and cities continue to grow, and getting fresh food to these environments in a way that's more efficient and sustainable is even more important."

So far, Bowery has raised $7.5 million from investors, including "Top Chef'" head judge Tom Colicchio and Blue Apron CEO Matt Salzberg.

The company says it's offering "the world's first post-organic greens," meaning the farm doesn't use any pesticides or chemicals. Fain points out that even organic farms are allowed use organic-certified pesticides and can be susceptible to chemicals used by neighboring farms. (The USDA says that organic farmers are allowed to use a designated list of fertilizers, like ethanol and chlorine dioxide, as long as they're organic, too.) These "post-organic" greens not unique to Bowery — most vertical farms today do not use pesticides or chemicals.

Bowery is one of many high-tech urban farming startups that have emerged in recent years. Also in New Jersey, AeroFarms started commercial production inside a 69,000-square-foot warehouse in 2016. Brooklyn's Square Roots, which made its first harvest in early 2017, is growing its produce inside ten 320-square-foot shipping containers .

Fain, a former marketing entrepreneur, says Bowery's name comes from the old Dutch word for farm: "Bouwerij." The first colonizers of Manhattan's Bowery neighborhood, families of freed slaves in the 1600s, also built large farms there.

"They fed the city," he says.