In Sonoma acreage for organic vineyards increased from 678 acres in 2011 to 1,163 acres in 2012 - an increase of 58%. Sonoma's recent increase put it at about 2%, just under the statewide average (2.7%), with its 58,300 acres of vineyards.
In Mendocino, the Ag Commissioner's office reports 3,735 acres now, down from 2011's 3,994 acres. In 2011, 28% of vineyards were certified organic or biodynamic.
Preliminary figures from the state show that statewide organic vineyards were about 12,700 acres, give or take (I'm waiting for clarification on some numbers that seemed inconsistent to me), or about 2.7% of the state's 462,023 acres of wine grape vineyards.
Overall, Napa supplies 32% of the state's organic wine grapes, Mendocino 31% and Sonoma 9%. The three counties combined account for 72% of organic vineyards in California.
Lake County had more than 500 acres of organic wine grapes in 2012, according to the California Dept. of Agriculture.
Using the state's data, organic wine grapes accounted for $72 million of wine grape sales in 2012.