The San Francisco-based start-up produces leafy greens in indoor farms and claims it can grow up to 350 times more per square metre than outdoor field farms.
Its crops are grown on six-metre vertical poles, using hydroponics - a water-only feeding system - and LED lights. No soil or pesticides are used. Infrared sensors monitor how the crops are faring so that the system can adjust light, heat and water flow accordingly.
Since it was founded in 2013, Plenty has raised $226m (£177m) from investors such as Amazon's Jeff Bezos, SoftBank's Vision Fund and Innovation Endeavors. This year it will expand its US operations and open its first farm in the Middle East.
Japan's Spread's Techno Farm concept
Japan's Spread is another firm developing automated vegetable-growing in vertical urban settings with its Techno Farm concept.
Floating farms near coastal cities
In the Netherlands, Peter and Minke van Wingerden are looking at opportunities to build more floating farms around the country, as well as in Asia. "We hope to make many more floating farms, but also welcome others copying us or coming up with concepts contributing to these goals," says Mr van Wingerden. "Healthy, sufficient food production is key to a better, cleaner, safer world."