Although Los Osos Valley to the northwest is also a distinguishable valley, its proximity to the ocean causes its climate to be colder with more fog and wind than Edna Valley. The floor of Edna Valley is approximately 120 to 300 feet above sea level. Major soils within the Edna Valley viticultural area are generally sandy clay loam, clay loam or clay. They are mostly hard, firm, sticky and plastic. They are also generally neutral to moderately alkaline.
Most soils are calcareous at some level of the surface soil or subsoil.
Soils in the surrounding mountainous areas above the 400 to 600-foot contour levels are shallower than in the valley and are of poor soil capability. Soils in Los Osos Valley are similar to those in Edna Valley but are generally heavier and of better capability. After evaluating the petition and comments, ATF has determined that due to the topographic and climatic features of Edna Valley, it is distinguishable from the surrounding areas. The boundaries proposed by the petitioner are adopted. Miscellaneous ATF does not wish to give the impression by approving the Edna Valley viticultural area that it is approving or endorsing the quality of the wine from this area.