Revol Greens - Tom Thompson and Erik McMullen.jpg

Tom Thompson, left, and Erik McMullen are pictured with trays of lettuce floating on water in the massive greenhouse in Cummings Valley that is now operated by Revol Greens.

Tehachapi may be the Land of Four Seasons, but under glass in Cummings Valley, there’s just one season. And it’s computer-controlled to be perfect for growing leafy greens.

Around the clock, 365 days a year, 14 different lettuce varieties are grown without pesticides, herbicides or other harsh chemicals — and packaged with no human hands touching the product.

Revol Greens recently began harvesting lettuce at the massive greenhouse on the floor of Cummings Valley that previously housed SunSelect Produce, Inc. Another smaller greenhouse to the north is operated by Millennium Pacific Greenhouses and began growing tomatoes in 2018.

The greenhouse now operated by Revol Greens was a 32-acre facility opened in October 2014 and later more than doubled in size. SunSelect grew tomatoes and bell peppers there. But in January 2020 the British Columbia-based firm announced the sale of the 65-acre greenhouse facility to Equilibrium Capital, an investment company focused on sustainable real estate investments.

Almost immediately, Equilibrium leased about half of the greenhouse to Revol Greens.

Founded in 2017, Revol Greens is the largest greenhouse lettuce producer in the U.S. In addition to its original location in Minnesota, the company has expanded to Tehachapi and in 2022 expects to begin operations in Temple, Texas.

Converting the greenhouse to grow leafy greens instead of tomatoes and bell peppers during the middle of the pandemic has been a challenge according to Tom Thompson, chief revenue officer and partner. But about 100 people are now employed by Revol Greens in California, including some who previously worked for SunSelect in Cummings Valley.

Growing lettuce

Erik McMullen grew up in Tehachapi. When he returned home after studying biological sciences in college, he wasn’t sure what he wanted to do. He found an opportunity with SunSelect and now is a grower with Revol Greens.

Although almost everything in the greenhouse is automated, staff carefully monitor activities from the seeding line to packaging.

The growing process begins as polystyrene trays (called boards) are packed with the growing medium — or substrate — that is essentially peat moss mixed with water. Different types of trays are used for the leafy greens and head lettuces grown by Revol.

After the growing boards are prepared, they make their way on a conveyor belt through the seeding drum. McMullen said a machine precisely drops seed onto the substrate, then the boards go through a water tunnel. The specially designed boards are then stacked and palletized and transported to the germination area.

The process for head lettuce is similar, although the substrate is packed into small cups on the boards with just one seed put (by machine) in each cup.

Depending upon the variety, the growing boards will spend two to five days in the germination area. Growers monitor the plants carefully, McMullen said.

“They’re looking for light,” he said of the tiny seedlings. They need to be moved out of the germination area to the greenhouse at exactly the right time.

The floor of the greenhouse is a large pond where nutrients are blended with water. Trays of seedlings are literally floated into the greenhouse and begin to send their roots into the water, gathering strength from the light and special plant-based nutrient source developed by Revol. According to the company’s website, it’s a 100 percent plant-based fertilizer alternative that is free of animal byproduct sources typically found in organic nutrients.

If pests develop, McMullen said, biological methods are used.

“We use good bugs to take care of bad bugs,” he said.

A variety of controls, including misting systems, keep the greenhouse environment at its best for the plants, with a typical temperature of about 69.8 degrees Fahrenheit.

Tehachapi offers a unique climate with over 278 average sunny days per year with milder temperatures, Thompson noted.

“This natural sunlight provides over 85 percent of the plant’s light needs, as opposed to indoor factory farms that rely on 100 percent on artificial light and energy use,” he said.

With perfect growing conditions, the plants are ready to harvest in two to four weeks, depending upon the variety.

The harvest

The harvest is also automated and mechanized, Thompson said. Without human touch, the lettuce products are cut from the growing boards (which are then cleaned and re-used) and channeled into bins before packaging.

Revol produces both retail and restaurant packages. The greens are blended to a customer’s specifications. Some products, such as salad kits, are packaged with other items. A California supplier provides packets of croutons, dressings or other components.

Within an hour of harvest, the greens are in the staging area ready to be packaged into three-pound cartons for foodservice customers or plastic packages for retail sale. Even the micro-perforations on the package tops are computer-adjusted to provide the best respiration rate for each blend.

Before heading out to customers, the packaged product is run through X-ray and metal detectors to ensure food safety and held at 37 degrees Fahrenheit until loaded onto refrigerated trucks.

Safety and sustainability

Food safety and sustainability are two important attributes of Revol’s method of growing lettuce, Thompson said. Healthy practices are employed throughout the greenhouse. Water coming into the greenhouse goes through a UV treatment process — and Thompson said 95 percent of the water is recycled. And although the peat moss substrate cannot be reused in the greenhouse, it is sent out to be composted, along with other green waste.

He added that the controlled growing environment requires just one pint of water per container of greens, compared to 12 gallons per container in the field. This means the annual equivalent of over 300 million gallons of water saved, Thompson said.

“We are hyper-focused on the challenging dynamic to deliver a high volume of fresh, quality leafy greens at a time when water and other resources are extremely limited,” he said. “The inspiration to start Revol Greens was to introduce a new option led by the brightest minds in sustainability and farming to address concerns that threaten the accessibility — and safety — of our fresh food supply.”

More information about the company is available at

Claudia Elliott is a freelance journalist and former editor of the Tehachapi News. She lives in Tehachapi and can be reached by email: