Inside a Vertical Warehouse Farm Hiding in Plain Sight

"The goal is to take the back-breaking work out of agriculture, and still offer really great produce at an affordable price."

Spinach towers in harvest.
Inside Plenty’s vertical farm, spinach towers are in harvest. Plenty

Nestled between massive nondescript warehouses housing a concrete factory and a roofing plant in Compton, Calif. sits a massive 100,000-square-foot farm with the potential to put out more than 2 million kilograms (4.5 million pounds) of greens every year. Unlike other farms you drive past, with miles and miles of open fields and workers picking, you wouldn’t know that this farm, operated by the startup Plenty, existed. It’s hidden in plain sight and home to cutting-edge technologies borrowed from other industries, including auto manufacturing, bioengineering, genetics, robotics, automation, agriculture and even energy.

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“We want to grow anything, anywhere, with massive yield and exceptional quality,” Andy Hotchkiss, the director of sales at Plenty, told a cohort of agriculture innovators who were there as part of the International Fresh Produce Association (IFPA) Fresh Field Catalyst Accelerator, a program designed to bring tech companies to the produce and floral industry and help make the supply chain more resilient and climate-resistant.

Climate change is changing what we can grow where

That last portion is particularly important, as the northern hemisphere enters the summer months with a bang. California and parts of the west, where more than one third of the nation’s fruits, nuts and vegetables are grown, experienced the first heat dome of summer, with temperatures reaching into the triple digits, a common sight in July but not in early June. That same heat dome has continued to push its way across the U.S., reaching the eastern U.S. in the coming weeks

Heat and climate change have had such a wide-reaching impact on growing seasons and agricultural areas that the USDA recently updated its plant hardiness map in late 2023. While the map is mostly used by home gardeners, it is also used to set crop insurance standards, which inform everything from crop risk management to agricultural investment all over the country. 

The updated map shows that across the U.S., the heat has risen by approximately 2.5 degrees Fahrenheit compared to the last map issued 11 years ago. Though the USDA said that it didn’t update the map due to climate change, farmers have noticed the shift for years

More recently, the markets have taken note with commoditized crops like corn futures rising more than 2.8 percent on June 6, the biggest intraday gain since May, thanks to the heat. As of the most recent data, prices per bushel are hovering around $448.75, which is still well off the high of $813.50 in April of 2022. A Cornell study from January showed that for every one degree Celsius of warming, major crop yields for commoditized crops like corn, soybeans and wheat fall by 16 percent to 20 percent, and gross farm income falls by 7 percent while net farm income drops by a whopping 66 percent. 

All of this data points to a growing problem: Climate change is impacting everything from what we can grow where to yields and futures. As a result, a new and growing number of Agricultural Tech (Agtech) companies, like Plenty, are finding ways to turn dense, urban areas into burgeoning farms that can feed thousands of people. 

Inside a cutting-edge vertical farm 

Vertical farms are not new, but it wasn’t until 2022 that the real vertical farming boom really got going in the U.S., with a number of indoor farms working to leverage everything from machine learning to robotics to produce more food, in less space, and with less climate impact.

The technology comes from NASA and was explored as a way to grow food in space. Advancements in lighting and LEDs have made vertical farming more profitable in recent years. Yet, the industry is still in a very nascent stage, but many think it offers promise, provided that the huge investment needed to build out these spaces can be recouped at the grocery store. Plenty is one of the buzzier startups, thanks to the massive investment (to the tune of $400 million) from financiers like Walmart and SoftBank (SFTBF)

Plenty's Compton farm
The exterior of Plenty’s Compton, Calif. farm. Plenty

Plenty currently has only one farm up and running—the one I visited in Compton—and according to Hotchkiss, it’s running at about 60 percent capacity. During the tour, we sat inside an enclosed viewing bridge where we could look down into the farm as long plastic towers of leafy greens like arugula, kale, and red and green lettuces moved from seeding through the growing cycle to packaging. 

Those towers, full of coconut husks (the planting medium that Plenty uses—they are completely “soil free”) and lettuces in various stages of growth, shuffle methodically along a conveyor attached to the high ceiling of the warehouse 24 hours a day. Seeds begin in dark grow rooms, and after a few days, robots move the pallets of baby lettuces out to be planted in those towers. A dexterous pinching robot grabs a set of the baby plants and tucks them neatly into individual slots in the towers before they head to the grow room full of LED lights, where they get 20 hours per day of simulated sunlight. The lettuces are fed a constant and measured stream of water and nutrients over a 28-day cycle to go from seedling to harvest to store shelf, and they’re continually checked and rechecked by a small staff of humans.

Advanced machinery and HVAC systems keep the temperature just right, and with the exception of a couple of workers on the floor who were cleaning up some of the coconut husk media and testing some of the plants, the entire farm is run by robots. It’s nearly a clean-room environment, with workers on the floor required to wear full-body gear to prevent contamination. While we were at the farm, an entire wall of green leafy lettuce slowly made its way out of the LED-lit grow room, and massive robot arms used in automotive manufacturing methodically rotated each long tower, placed it on a harvesting conveyor belt, a cutting machine harvested the lettuces, then sent them on packaging, while the tower stayed on for cleaning and replanting. 

Plenty says that the operation uses approximately 90 percent less water than conventional farming, and they do their best to recycle or reuse everything. The Compton location is not yet on renewable energy (those robots and lights use a tremendous amount of power), but the company says it is working off of two local electrical grids–one of which acts as a backup if the other goes down. Power consumption and water use are huge costs, both financially and for the climate, and, while there are benefits to vertical farming, it is very resource-intensive. The used coconut husk, roots, and remainder of plant material are composted, but the company is working on finding other uses for it. The plastic towers are sanitized and reused, and, because the plants respire so much water, the specialized HVAC and condenser systems recapture that water and then recirculates it in the vertical farm. Harvested produce that doesn’t meet “perfect” standards is then sent out to food waste reduction firms like Imperfect Foods and Misfits.  

Spinach post-harvest.
Spinach post-harvest. Plenty

Taking the back-breaking work out of agriculture

Plenty has relationships with a number of local and nationwide grocers, and the lettuces from the Compton farm can be found in Whole Foods, Walmart, and local Southern California chains like Bristol Farms and Northgate. The company said its products are available in approximately 200 stores. The produce is not organic but rather “pesticide-free” since it’s grown in a clean-room environment. Because there’s no soil medium, consumers don’t have to worry about washing the greens before consuming them, either.

The Compton farm is Plenty’s second location–its first was in San Francisco and served as R&D, but the company chose to move to Compton and retrofit an existing warehouse space for the lettuce farm.

Hotchkiss said they learned a lot when retrofitting the brownfield site, noting that they had to upgrade everything from the i-beams that run along the roof so they could support the towers and plants, to regrading the floor for drainage and water recapture, and upgrading the HVAC system. The goal is to have farms providing food for most grocery stores within a day’s drive to help cut down on transportation impact, and keep the lettuce as fresh as possible when it hits the shelves and consumers’ hands. Plenty is also committed to hiring 30 percent of its workforce from the surrounding area in Compton. Most of the employees at the Compton plant have advanced degrees in everything from biology to machine learning and A.I.

The unmarked warehouse farm just celebrated its first year in operation in May, and Plenty has ambitious goals ahead. The company is looking to scale the operation to other locations around the country. It’s currently building a strawberry farm in Richmond, Va., which should open later this year. Strawberries are particularly difficult to harvest using robotics because the berries are so soft and come in different sizes and shapes. At the same time, however they offer the company a higher margin because they cost more. 

“The goal is to take the back-breaking work out of agriculture, and still offer really great produce at an affordable price,” Hotchkiss told the tour. “We leverage technology, robotics and more to make this all happen.” 

Inside a Vertical Warehouse Farm Hiding in Plain Sight