Before irrigation systems became available and practical, dry farming was standard practice for planting and managing wine grapes in California. Dry farming is still possible and successfully used by some growers, but it is site-specific and dependent on annual rainfall, climate, soil type and grape variety. The economics of dry farming are a key consideration in relation to grape yields and prices.
Dry farming wine grapes depend on residual soil moisture to meet the water requirements for grape vine growth and berry development (Chatterton, 196). Even in California’s dry Mediterranean climate, the water retained in soils from winter rains can be sufficient to support grape production throughout the growing season without supplemental irrigation.
Dry farming techniques can improve grape and wine quality. Many growers have said that they trade quantity for quality when dry farming. Although dry-farmed vineyards may yield less than irrigated vineyards, the fruit that is produced often has more concentrated flavors and a deeper expression of quality taste. Tablas Creek Vineyard in Paso Robles believes that their dry-farmed berries are essential to the balance and expression of their wines.
Dry farming can also have significant positive impacts on the environment and improve the sustainability of vineyards. By not irrigating, dry farmers reduce the water footprint of the vineyard. According to Frank Leeds (2003), studies in Napa Valley shows that he is saving a minimum of 16,000 gallons of water an acre a year by dry farming his vineyards, compared to those that only lightly irrigate. If vineyards can conserve fresh water, not only will they be contributing to water conservation, but also reducing their dependency on a highly demanded resource, particularly in areas of groundwater overdraft (Hargreaves & Mary, 109).