The following charts are updates of similar ones first presented here in 2015; they now include values through the 2019 harvest. They are helpful to appreciate the divergent paths that the wine grape industries in each county have been experiencing in recent years.
This difference can be explained in large part by the unequal crop options that are available for producers in the different counties. Farmers in much of Santa Barbara County have a large range of potential crops to choose from, including citrus, berries, flowers, cannabis, etc. The notable decline in wine grape acreage in that county in recent years likely reflects the shift in cropping to these other options which may offer better returns currently. Conversely most of the wine grape regions of San Luis Obispo County do not have the same number of crop options, due to the limitations of climate, water availability, and County restrictions on crops such as cannabis. Wine grapes are a very suitable crop for the particular growing conditions in the county, but the lack of alternative crops presents additional challenges during periods of excessive wine grape supply.
The charts tend to speak for themselves, so it will be left to the reader to draw their own conclusions.
The data sources are the Ag Commissioner Crop Reports for SLO and SB Counties. Four of the charts use dollar amounts adjusted for inflation using the CPI Inflation Calculator, to Oct 2020 values.
The Excel data files used to make these charts are available for download on the UCCE website.