Still, the wildfires happened just before some growers planned to start harvesting their avocados and lemons. And farmers who are relieved their entire crop was not wiped out are still worried about having enough workers when they will need them later in the season, because it is still unclear how many people lost their homes.

“Everything has been thrown up in the air,” said Lisa Churchill, who grows avocados and specialty tangerines, like the pixie variety, in the Ojai Valley. Ms. Churchill said she believes she lost about half of her avocado crop and about 20 percent of her mandarins. “We don’t know what impact this will have on our ability to put together a crew,” she said.

Many farmers said the devastation would have been considerably worse were it not for the workers on the front lines, frenetically spraying water from hoses and small water tanks mounted on their backs. Sometimes workers resorted to shoveling sand onto smoldering vegetation.

Some 36,000 farmworkers, the majority of them immigrants, work in Ventura County. About nine out of 10 farmworkers in the area are illegally in the country, according to independent estimates.

One Mexican worker, who gave only his first name, Fermin, evacuated his wife and 5-year-old daughter from their trailer park, then went to the farm where he works.