Grapes are successfully grown in Colorado, a fact that surprises many who associate the state primarily with mountains and high-altitude ski resorts. While the state is not a traditional grape-growing power like California or Washington, a small but thriving commercial viticulture industry exists. This industry relies on specific geography to cultivate both classic European wine grapes and cold-hardy hybrid varieties. The successful cultivation of these crops is a testament to microclimates that mitigate the challenges of a high-desert environment.
Commercial Grape Growing Regions
Commercial grape growing is concentrated almost entirely on the state’s Western Slope, away from the more populated Front Range. This region is home to two federally recognized American Viticultural Areas (AVAs), which designate areas with unique grape-growing characteristics. The Grand Valley AVA, located near Palisade and Grand Junction, is the most prominent and accounts for the majority of the state’s total grape production.
The vineyards in the Grand Valley sit at elevations between 4,000 and 5,000 feet, nestled in a high-desert river valley carved by the Colorado River. Further southeast, the West Elks AVA encompasses the North Fork Valley, including areas around Paonia and Hotchkiss. This second AVA is significantly higher, with vineyards planted between 5,400 and 7,000 feet, making it one of the highest-altitude viticultural regions in the world. These areas were chosen because the surrounding mesas and canyons create favorable microclimates, offering protection from harsh weather and providing access to irrigation from snowmelt-fed rivers.
Defining Climatic Factors
The climate that allows grapes to thrive in Colorado is defined by high altitude and desert characteristics. The high elevation provides intense ultraviolet (UV) light exposure, which contributes to thicker grape skins and concentrated flavors and colors. A distinctive feature is the dramatic diurnal temperature shift, where hot summer days are followed by very cool nights. This temperature swing is beneficial because the cold nights slow the grapes’ respiration, helping the fruit retain acidity while the daytime heat drives sugar development.
The short, intense growing season, typically around 180 days, means growers must choose varieties that ripen quickly. The most significant challenge is the risk of Low Temperature Injury Events (LTIEs), which are extreme cold snaps that can destroy vines during the winter. To protect the Vitis vinifera vines, many growers must physically bury the canes with soil or straw, a labor-intensive practice necessary to insulate the plants from lethal sub-zero temperatures. This semi-arid environment also necessitates regular irrigation, which is reliably sourced from mountain runoff, supplementing the low annual rainfall.
Successful Grape Varieties
The unique conditions of Colorado’s AVAs allow for the cultivation of several classic European grape varieties, known as Vitis vinifera. Among the red grapes, Cabernet Franc, Merlot, and Syrah show consistent success, benefitting from the high-desert sun to achieve ripeness while maintaining structure from preserved acidity. Cabernet Franc is often cited as a standout variety, as its earlier ripening cycle helps it avoid the late-season cold snaps that challenge other varieties like Cabernet Sauvignon.
White grapes such as Riesling, Chardonnay, and Viognier also perform well in the high-altitude vineyards. Riesling, in particular, thrives due to the cool nighttime temperatures that help it retain bright, crisp acidity, resulting in wines with intense aromatics. In higher or more vulnerable locations, growers rely on cold-hardy hybrid varieties, such as Marquette, Frontenac, and Traminette, which are bred to withstand significantly colder winter temperatures without needing extensive protection. Beyond wine production, a smaller market exists for table grapes, including seedless cultivars like Himrod and St. Theresa, selected for their hardiness.