California's walnut ground in 2017 ballooned to 400,000 acres, a 10 percent increase from 2015, the National Agricultural Statistics Service estimates.

Of the total acreage, 335,000 were bearing and 65,000 were non-bearing, the NASS office in Sacramento noted in a walnut acreage report issued May 23. Walnut orchards added 20,000 bearing acreage last year from 2016, and productive walnut trees statewide have jumped from 255,000 since 2010.

The estimate comes as a result of an industry-funded, voluntary survey of about 4,900 walnut growers, who provided detailed data about such things as variety and year planted. The data reflects tree removals from about 7,000 acres in the past two years, including trees that were pulled out after last fall's harvest, NASS officials say.

Of the walnut acreage reported, Chandler remains the leading variety with 121,524 bearing acres, followed by Hartley with 30,172 bearing acreage, the agency reports. Chandler also accounted for 59 percent of the non-bearing acreage.

Butte County has the largest acreage with 16 percent of the total, followed by San Joaquin with 14 percent and Tulare with 10 percent, according to the survey.

To view the full report, click here.