For years, Fresh Pac International, Oceanside, Calif., has gotten good results growing most of its roma tomatoes in shade houses in Baja California.

This year, the company also moved its vine-ripe, cherry and grape tomatoes indoors and has enjoyed better yields and improved quality compared with field-grown product, said Brian Bernauer, director of sales and marketing.

“Consequently, demand is up also,” Bernauer said.

The trend toward protected agriculture continues to expand throughout Mexico as growers there look for ways to improve yields and quality while keeping pests at bay.

Joe Bernardi, president of Bernardi & Associates Inc., a Nogales, Ariz.-based brokerage with an office in San Diego, said nearly all the tomatoes the company deals with are grown in shade houses.

“The industry as a whole asks for shade house product,” he said. “It’s a cleaner tomato. It’s better conditioned. It’s a better-quality product.”

San Diego-based Royal Flavor LLC sources nearly all of its vine-ripe, grape and roma tomatoes from shade houses or greenhouses in three areas of Baja California, said Steve Yasuda, sales manager.

“Anything else is a thing of the past,” he said.

Santa Ana, Calif.-based United Greenhouse LLC grows tomatoes-on-the-vine year-round in hydroponic greenhouses in Baja California, said owner Ari Canelos.

The company has about 100 acres of greenhouses.

“Hydroponics really (does) help with the quality,” Canelos said.

Ten years ago, 100% of the tomatoes that San Diego-based Andrew & Williamson Fresh Produce grew in Baja California were grown in open fields, said Mark Munger, vice president of marketing. But as disease began to set in, the company started moving its fruit into shade houses.

Benefits of shade houses are many, Munger said. Growers need fewer pesticide applications, they can reduce their water use because there’s less evaporation, and the amount of packable product increases to as much as 95% because tomatoes are grown in such a pristine environment.

Higher production per acre helps offset the significant cost of building shade houses, Munger added.

“I think we’re doing a better job of growing,” Bernauer said. “And a lot of that has to do with growing indoors.”

Fresh Pac did not produce vine-ripe or cherry tomatoes last year because growers could not maintain consistent quality, he said.

“We had times when the quality would be great,” he said, “but there were times when it would suffer due to outdoor variables.”

“Indoors, the quality has been outstanding, and I think it’s actually grown the category for us,” he said.

Andrew & Williamson became so enamored with the technology that the company considered growing all of its tomatoes in shade houses.

“We decided we wanted to grow the highest-quality produce possible at any given time of year,” Munger said. “For us, the shade house is a tool to accomplish that.”

Shade houses have their drawbacks, though.

They’re hard to dry out when the weather gets cool and rainy, and those damp conditions can cause mold on the fruit.

That’s why Andrew & Williamson decided to use shade houses when they’re needed to produce top-quality product, but not at certain times or in certain regions where a better piece of fruit can be grown in an open field.

Shade houses play an important role in limiting disease in Baja California during the spring and summer, Munger said, but they play less of a role in Culiacan in the fall when the weather turns rainy.

Today, it’s hard to drive through Baja California or central Mexico without seeing shade houses, Munger said. Five or 10 years ago, they were a rarity.