“Policymakers and the people in charge of water departments are not consulting with the gardeners,” said Alvaro Huerta, a professor of urban and regional planning and of ethnic and women’s studies at California State Polytechnic University in Pomona. “They’re not seeing what the negative impact is on them. They’re pretty much invisible. It’s an invisible work force that everyone depends on.”

The impact of the drought on this gray economy has been overshadowed by job losses in the state’s giant agricultural industries, which have left hundreds of acres fallow because of the lack of water.

“I think it’s a 20 percent or 25 percent cut in business in the last six months,” said Gonzalez, who started his company 22 years ago. “All my friends, they tell me the same thing. Some people stopped gardening.”

His company used to have 11 men serving 420 customers throughout the San Fernando Valley, but he had to lay off two employees in the past six months. He said he lost 20 customers in that time and the ones remaining are asking for less frequent service.

“Oh, yeah. I lost jobs,” said Jaime Gonzalez, the owner of La Niña Landscape in North Hollywood. “Some people say now, ‘Just come once a month.’ Now it’s less hours.”

As more water districts struggle to abide by Gov. Jerry Brown’s mandatory 25 percent cut in water use by increasing incentives for homeowners to rip out their thirsty lawns and flowers and replace them with gravel and drought-resistant plants, gardeners are finding themselves with less and less work.

Gardeners, most of them small crews of Mexican immigrants who make their rounds in pickup trucks laden with gardening equipment, are losing their customers.

The state’s historic drought, which has thrown two-thirds of the state into extreme or exceptional drought conditions , is cutting into a huge sector of California’s underground economy.

LOS ANGELES — On any given day, the buzzing sounds of lawn mowers and leaf blowers resonate through leafy residential neighborhoods from ritzy enclaves in Beverly Hills to working-class areas in Van Nuys.

Jaime Gonzalez, the owner of La Niña Landscape in North Hollywood, California, said his business has declined about 25 percent in the last six months because customers are ripping out lawns. Haya El Nasser

Gardeners are not an organized bunch, largely because many of them are undocumented immigrants. In California, gardening has long been the ideal entry job for newcomers to the United States. Japanese immigrants did it as far back as the late 1800s because they weren’t allowed to own farmland, and many eventually established nurseries.

“It was a way for them to make a living and to avoid discrimination they were facing in the farmland economy,” said Huerta, who has written on the topic. “It’s something that has always attracted newcomers, particularly immigrants, because it wasn’t regulated, you didn’t have to have a license.”

As second and third generations of Asians became more educated and left the gardening business, Mexicans began pouring in after the Immigration and Nationality Act of 1965 allowed for reunification of families with relatives who were American citizens.

“A lot of them were coming from the countryside, like my mother and father,” Huerta said. “It’s a natural transition to go from the countryside and work in the fields or work the land in the city.”

He estimates that there are 10,000 gardeners working in crews in Los Angeles County alone. “It’s pretty huge,” he said. “Look at the amount of homes, the amount of lawns. This is a very important sector.”

But it has not been quantified because it’s a shadow economy.

“For Mexican men particularly, it’s a very important part of the economy,” said Vinit Mukhija, an associate professor of urban planning at the University of California Luskin School of Public Affairs.

Signs of the magnitude of this underground gardening economy were evident in the mid-1990s when the Los Angeles City Council barred using gas-powered leaf blowers in residential areas because of concerns over noise and air pollution and imposed stiff fines for violators ($1,000 and up to six months in jail).

Latino gardeners organized and held candlelight vigils, protest marches and a weeklong hunger strike. Huerta said they were successful in framing the debate as between the “haves against the have-nots” and won a significant victory: The ban is on the books, but the fines are minimal and rarely enforced.

But today it’s not the law but a natural disaster — the worst drought in recorded state history — that is threatening these green urban workers.

The Association of California Water Agencies reports a surge in turf rebate programs in communities across the state. The Metropolitan Water District of Southern California recently doubled its incentive to replace thirsty turf from $1 to $2 per square foot. As a result, requests for the rebates in one month alone amounted to 2.5 million square feet of turf removal, the equivalent of removing 1,665 typical Southern California front yards. Additional funding for the program may be approved next week.

In Laguna Beach, eligible customers can get $3 for every square foot of turf they remove. In the Foothill Municipal District, water customers can receive up to $800 in rebates for removing thirsty lawns and replacing them with native plants, mulch or synthetic turf.

“They put gravel, or they put plants that don’t need too much water, and they don’t need gardeners anymore,” said Gonzalez, who has had to cut the hours of the workers he hasn’t laid off.

He is now trying to get into the no-grass gardening business. He just worked on a project to replace a lawn with low-water landscaping.

“There’s a lot of interest from folks in redoing their landscape, and the big driver in the last year has been incentive programs to remove turf,” said Sandra Giarde, the executive director of the California Landscape Contractors Association. The group does not represent the small residential garden services that are not licensed or insured.

“In communities where rebates are offered, there’s definitely been an upswing in calls, but the belief is that the rebate money would be able to cover removal and installation of a new landscape,” she said. “Some are disappointed. It’s designed to cover turf removal, not the landscape of your dreams.”

Nevertheless, Huerta said it’s the immigrant gardeners who are getting the short end of the stick.

“You have rebates for homeowners, but there’s no rebates for the gardeners,” he said.