Mendoza is divided into various regions for the cultivation of vines of excellent quality.
Two of them stand out as the most recognized wine growing areas due to their prominent conditions: Valle de Uco and Luján de Cuyo
Luján de Cuyo
Known historically as the ‘prime zone’ for wine-growing in Mendoza. Its high elevation location in combination with a semi-desert climate and low-nutrient gravelly soils provide ideal conditions for cultivation of high quality fruit. The influence of Mendoza River, one of the main sources of water for irrigation of the region, confers identity to the area, influencing the soil composition and the determination of productive areas.
Here can be found outstanding wine growing districts as Agrelo, Las Compuertas, Perdriel and Vistalba. The altitude in this area varies between 800 m (2624 ft) and 1100 m (3308 ft) above sea level. The cool temperate climate ensures the optimum ripening of the grapes. The soil is made up of fine sediments of alluvial origin, while the subsoil contains sand silty clay sediments.
Valle de Uco
This valley will surprise you with its magnificent scenery and its privileged location at the foot of the Andes Mountains. Irrigated by the waters of the Tunuyán River and other mountain tributaries, this area is a true productive oasis.
It includes the territories of Tunuyán, Tupungato and San Carlos departments, within which the most notable districts are Los Chacayes, Altamira, El Peral, Gualtallary, La Consulta, Los Árboles, Villa Bastías and Villa Seca. The altitude varies between 900 m (2952 ft) and 1400 m (4593 ft) above sea level. It has a wide temperature range. Winters are harsh and the average temperature is generally lower than in the center of the province. The soils are of alluvial origin, with great presence of pebble stones of variable size.
Mendoza is characterized by a high-altitude, semi-desert region. The Andes Mountains influence Mendoza’s climate because the tall peaks block the humid air coming from the Pacific Ocean, dropping humidity levels. The climate is temperate and particularly dry, with many sunny days throughout the four seasons (+90% of the days with clear skies per year).
The annual precipitation varies between 150 – 220 mm and rainfall is more frequent during the spring and summer. In winter, these precipitations may cause light snowfall at lower elevations and heavy snowfall in the high mountains.
The climatic conditions -temperature range and low relative humidity- are very favorable for vine growing because they contribute to achieve the optimal maturity of naturally healthy grapes.
Soils in Mendoza consist mainly of the disintegration and decomposition of rocks and minerals from the Andes, dragged by the action of winds or river waters.
In cultivated areas, near large rivers, alluvial soils predominate in the highest steepest slopes, and alluvial-lacustrine soils prevail in areas with lower relief and far from the mountain range.
Soils show a great diversity of textures, even in small spaces. They may change from sandy to silty-clayish in a few-meter distance; or show surface rocks in contrast with rocks at greater depth in test-pits dug very close to one another. The presence of stones is remarkable; boulders of varied sizes, appearing with greater abundance in the areas of the Mendoza piedmont.
Snowmelt is the main water source for irrigation: clear mountain water is distributed through a millennial and ingenious system of canals and ditches devised by indigenous people called huarpes. According to irrigation shifts, water is delivered and it may be used immediately for surface irrigation or stored in ponds or dams for later use. This allows for the agronomist to decide irrigation quantity and frequencies according to the phenological growth stage of the vine.
Another source of irrigation is the extraction of water stored in underground aquifers.