Walmart recently announced their investment in vertical farming startup Plenty as part of the South San Francisco company's $400 million Series E funding round.

Essentially, this will allow Walmart to start shipping leafy greens from Plenty's southern California farm to various locations across the state this year. Walmart will also gain a seat on Plenty's board of directors.

"We believe Plenty is a proven leader in a new era of agriculture, one that offers pesticide-free, peak-flavor produce to shoppers every day of the year. This partnership not only accelerates agricultural innovation but reinforces our commitment to sustainability by delivering a new category of fresh that is good for people and the planet." - Walmart Chief Merchandising Officer Charles Redfield.

In addition to Walmart taking an interest in vertical farming, Kroger also announced that it's expanding an initial test run with a vertical farming startup to 380 of its stores, and Publix has experimented with on-site hydroponic farming in similar structures.

Plenty runs warehouse-like farms in South San Francisco and Compton, California. The crops are illuminated by LED lights, stacked in tall columns, and then planted and harvested by robots, which allows them to grow in a fraction of the space required for a traditional farm.

"Plenty's unique farming system unlocks industry-leading crop versatility and unit economics by enabling indoor growing year-round. Our farms can be sited anywhere, allowing us to put fresh fruits, greens and vegetables on shelf at all times, at speed, for maximum freshness." -Arama Kukutai, CEO of Plenty.