Here's why the cost of lettuce is skyrocketing in California

The primary ingredient in almost any salad is lettuce. And unfortunately for those who sell lettuce, like grocery stores, restaurants and other suppliers, that critical ingredient is now in very short supply.

"Even at the restaurant depots and the big warehouse stores that you get bulk items at, we can't even get cases of lettuce anymore," said Sue Jin Oh, who works at M&M Deli in Riverside.

"It's getting hard. We're paying higher prices for it, and we can't raise our prices. We just raised the prices not too long ago," she said.

Oh said they now buy most of their lettuce from grocery stores, where lettuce is going for $3.50 per head.

"We're struggling finding lettuce. We're trying to find lettuce at the cheapest cost so we can actually use it for all the sandwiches, but it's getting hard," she described.

At a Wendy's fast-food restaurant in Apple Valley, a sign on the front door indicated: "The lettuce we use for sandwiches has been impacted by adverse weather in the growing region; this is an industry-wide issue."

But one expert said the biggest problem is not the weather.

"The primary production source of lettuce this time of year is the Salinas Valley," said Bruce Babcock, an agricultural economist and professor at U.C. Riverside. "And they are having a terrible crop. The crop has been infected with a virus, and their yields are down 75%."

Babcock said the virus is known as INSV, the impatiens necrotic spot virus.

"It's been around 2 or 3 years. It's been getting worse and there really is almost no mitigation for this virus," he said.

Other growing regions in the country aren't having this problem. Consequently, Babcock said it's possible that prices could return to normal levels when farmers in Arizona and surrounding growing regions make their seasonal switch to growing lettuce in the coming weeks.

"The production starts in late November, and really gears up into December. So we probably won't see relief in prices until December," he explained.

But if the situation doesn't improve by next year, he said it's going to be very difficult for the growers in the Salinas Valley to continue farming lettuce.

"They cannot make money with their crop yields so low. So I think we're going to be looking for alternative sources of supply," said Babcock, who believes farmers in San Luis Obispo County, Santa Barbara County and even Ventura County might begin to look into the possibility of farming lettuce in larger numbers in 2023.

"I think there's plenty of incentive for other growers to start thinking about getting into contracts and growing lettuce for October and November next year," he said.