One of the robots is 1,000 pounds and about the size of a car. It picks up the trays of plants and transports them around the greenhouse. A second machine, a robotic arm, is responsible for all the fine manipulation tasks, like seeding and transplanting.

Start-up Iron Ox created a fully autonomous farm in San Carlos, California. The hydroponic indoor farm relies on two robots to plant, care for and harvest produce.

The robots at Iron Ox use machine learning and AI to detect pests and diseases. They can remove infected plants before the problem spreads.

As a tray of plants matures, the mobile robot carries it to the processing area. Here, the robotic arm moves baby plants in densely packed trays to containers with more space. This optimizes space efficiency, because throughout their life cycle, plants are only given the room they need.

Co-founder and CEO Brandon Alexander claimed that Iron Ox is able to do the equivalent of 30 acres of outdoor farming in just a single acre on its robotic farm. The company wants to build more small farms near urban centers so produce is fresher upon arrival.

"Right now fresh produce really isn't all that fresh. It's traveling on average 2,000 miles from farm to grocery store, which means a lot of people are eating week-old lettuce or strawberries, " Alexander explained.

The robots at Iron Ox also use machine learning and AI to detect pests and diseases. They can remove infected plants before the problem spreads.

"So it's not just that the robots can move plants around and very efficiently, it's also that they can help you avoid ever having a plant go bad," co-founder and CTO Jon Binney explained.

Iron Ox is not the only venture-backed indoor farm. Others, like Bowery and Plenty, also aim to use the latest technology to sustainably produce crops near cities.

However, Iron Ox is the first to fully automate the growing process and completely design its system around the robot's capabilities.