Close-up of unripe walnuts with textured green husks on a tree, surrounded by waxy green leaves, backlight by soft sunlight.
The walnut harvest in San Joaquin County is the largest in California. The crop is the county's fifth most valuable, with prices growing significantly from a downturn last year. (Photo courtesy of California Walnut Board and Commission)

Fall is harvest time, but one of San Joaquin County’s biggest cash crops is coming in significantly lower than normal after summer’s intense heat, and that could mean higher prices for Californians.

Agricultural Commissioner Kamal Bagri said walnut growers are seeing yields 30% to 45% below average, and the size of the nuts is also smaller.

The effect on prices at supermarkets is yet to be seen, but Bagri said consumers may want to brace themselves. “Be ready to pay more,” she warned.

While walnuts fare fine during the hot summers around Stockton, they need breaks from the heat as well, Bagri said. Even during the evenings, cool temperatures have been rare this year. Stockton reported a record number of days with high temperatures above 100 degrees — 41 days — surpassing the previous record set in 2022. 

A peaceful tree-lined orchard path with fallen leaves on the ground on an overcast day.
Walnut hulls aren’t opening as readily this season, and it’s harder to shake the trees so the nuts fall from the branches, allowing them to be easily collected. (Photo courtesy of California Walnut Board and Commission)

During harvest time, growers need less heat and more moisture. This season, the walnut hulls aren’t opening as readily. It’s becomes harder to shake the trees to make the nuts fall from the branches, allowing them to be easily collected. The wait is delaying harvest, Bagri said.

San Joaquin County is the state’s largest producer of walnuts, with about 71,000 acres of groves, many centered around the town of Linden, east of Stockton. The county is a leading producer of the Chandler variety of walnuts, treasured by consumers for their light color.

Walnuts are the county’s sixth most valuable agricultural commodity — behind milk, grapes, almonds, cherries and eggs. Even at a time of increasing urbanization in California, agriculture remains a powerhouse in the county. The total gross value of all products and crops in 2023 was $3.2 billion and accounted for 34,000 jobs, about 10% of the county’s employment, according to an annual report from the agricultural commissioner.

Walnuts alone had a gross value of $149.3 million in San Joaquin County in 2023. And statewide, it was a banner year for the industry, said Christine Lott, spokeswoman for the California Walnut Board and Commission.

Walnut groves typically produce fewer nuts following a giant harvest like last year’s, so lower production was expected in 2024. But the sweltering summer made things worse, especially during July, when soaring temperatures hindered the ability of kernels to form inside the walnut shells, Lott said.

The U.S. Department of Agriculture predicted California’s walnut production would be 670,000 tons this year, down 19% from 2023, the board reported in September.

Still, Robert Verloop, the board’s executive director and CEO, struck a hopeful tone at that time.

“We feel confident about the upcoming crop year,” Verloop said in a statement. “We continue to focus on delivering quality all the way to the consumer.” 


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