Field Trip Friday: Wine production in Willcox

(Source: 3TV/CBS 5)

By Rod Keeling, Keeling Schaefer Vineyards


Central to the Willcox Wine Country story is Arizona and all the things that make it the unique place that it is. Arizona is a place without equal, full of incredible natural wonders, one-of-a-kind places and a long and storied history you won't find anywhere else in the world.

The Willcox region epitomizes these characteristics of our state with mountains that reach 11,000 feet and high altitude valleys and foothills that are ideal for wine grape production.

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The Willcox region is at the center of the Basin and Range geographic that characterizes the southeast corner of the state, as well as northern Mexico and parts of New Mexico and west Texas.

This area is dominated by almost parallel mountain ranges interspersed with high altitude basins, or valleys. Due to the primarily dry climate, large diurnal (day/night) temperature variations occur in the Willcox region.

The swings can be as large as 50 °F (28 °C) in the summer months. Almost all of Willcox wine vineyards are found in an altitude band of 4,000 to 5,500 feet above sea-level.

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The Willcox region has an average annual rainfall ranging from 8- 20+ inches, which comes during two rainy seasons with cold fronts coming from the Pacific Ocean during the winter and a monsoon in the summer. The monsoon occurs toward the end of summer and early fall, during the wine growing season.

In July, August and early September, the predominant wind direction shifts to the southeast, pulling tropical moisture up from Mexico. As a result, the dew-point rises dramatically for a brief, summer rainy season. During this time, the air contains large amounts of water vapor. This higher moisture and summer convection brings lightning, thunderstorms, wind and torrential, if usually brief, downpours.

Over 74 percent of all of Arizona's total wine grape production occurs in the Willcox Basin, which has been designated an American Viticultural Area by the United States. The primary area is called the Willcox Bench, a rising alluvial fan slightly above the valley floor at elevations of 4,300 to 4,550 feet above sea level.

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The first vineyard on the Bench was planted by RW Webb in 1984 and now provides wines for Caduceus, Merkin Vineyards, Arizona Stronghold and others. Bodega Pierce, Zarpara, Carlson Creek and Pillsbury are also located on the Bench.

The Willcox Bench is the classic Basin growing area. It is warmer during the day, cooler at night and less rainfall 7-9 inches during the monsoon summer than the foothill areas. The soils are varied, but are more traditional agricultural soils, as much of the Bench was previously farmed with annual crops of cotton, peppers, onions, alfalfa and grains.

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Sandy loam soils dominate with areas of gravely loam along the ancient washes that flow after a hard monsoon rain. Some of the Willcox production is in the Chiricahua Mountains foothills, like the area where Keeling Schaefer Vineyards, Aridus, Colibri Vineyards, which supplies fruit for Page Springs Cellars and others are located.

This area is the classic Range location at altitudes of 4,850 to 5,400 feet above sea level. The climate is cooler during the day, shaded in the late summer by monsoon build-up clouds, and much more rainfall. The average rainfall for the last 75 years of records at the Chiricahua National Monument is almost 17.5 inches annually, and the average August high temperature is about 88 degrees.

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The growing season gets a later start and a later harvest in the foothill area, as much as 2-4 weeks in most years compared to the Bench. The soils are considered upland sandy loam with cobble. At Keeling Schaefer, the cobble, a smooth river-washed rock from fist-sized and up, makes up about 50 percent of the soil profile of the root-zone of the vines. The cobble is mostly comprised of Rhyolite volcanic rock, which is the kind of rock that makes up most of the rock formations in the Chiricahua National Monument.

The water for the vineyards, as well as all agriculture and other uses in the Willcox Basin, is groundwater. Much of the water is from rain run-off during the monsoon that recharges the Willcox aquifer. The Basin has the capacity to hold millions of acre-feet of water, but it is finite. This run-off and recharge have been occurring for thousands of years and the resulting water is really a "bank account" of incredibly pure, high-quality water that feeds the vines. However, agriculture and other uses are pumping water out of the basin at a 5 to 1 overdraft, depleting the bank account and lowering the water table.

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The development of the wine industry in Willcox can help change this overdraft problem by using less water than traditional crops. If all 60,000 acres of irrigated farmland in the Willcox Basin were planted to grapes, the overdraft would be reduced to a more balanced condition, where natural recharge would replenish the withdrawals. All of these characteristics of soil, climate, water and elevation shape the vines and the production of grapes and wine in Willcox Wine Country. All great wine growing regions in the world have large diurnal temperature swings.

[SPECIAL SECTION: Good Morning Arizona]

Grapes need well-drained soils to survive, and sandy, rocky soils are great and add much to the wines' character. Two characteristics that are unique about the Willcox region are its high elevation and the monsoon season. There are very few grapes growing regions in the world as high as the elevations in Willcox with a monsoon season.

The effect on the wine is really unique to Arizona.

The modern Arizona Wine industry was established in the early 1980's, following the development of experimental vineyards by the University of Arizona.

Studies led by Dr. Gordon Dutt were completed demonstrating the feasibility of various wine growing regions. In 1982, a collection of new laws enabled the Arizona Farm Winery Act. The first licensed wineries in Arizona were formed shortly after the enactment of the new law. Dr. Dutt himself formed Sonoita Vineyards, the first winery of this modern era. The Arizona Wine Growers Association was formed in 1983. In 2005 there were 9 wineries in the state. Today there are 103.

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