Covelo is an unusual and rather remote AVA located in Mendocino County, 45 miles (72km) north of the town of Ukiah. It is distinguished by the bowl-shaped Round Valley that forms part of the appellation along with Williams Valley and the surrounding foothills. Covelo was awarded AVA status in 2006 and, today, less than one hectare (2 acres) is planted to vine, with no wineries currently in operation.
The area's high peaks provide protection from the influence of the Pacific Ocean and give it a decidedly continental climate (to an extent not often found in California). Hot, dry summers give way rapidly to the kind of cold winters more often associated with areas much further inland. While there are obvious drawbacks to this, including a reduced growing season and frost risk, the cold winter temperatures protect Covelo from Pierce's disease – a vine-killing bacterial disease.
Covelo's deep, loamy soils are as atypical of its neighboring Californian wine regions as its climate and create their own advantages and challenges for viticulture. High in nutrients and relatively free draining, these soils promote healthy, prolific vine growth, creating the need for rigorous vineyard management. Crop thinning and leaf plucking are just two of the techniques used here to reduce yield sizes and consequently increase fruit quality.
The key challenge here is the very short growing season, which makes Covelo somewhat marginal as a winegrowing region. Its AVA title was granted on the basis of the region's potential – the conditions here were too unusual to ignore – but the appellation is still "on trial" while experimentation continues into which grape varieties will thrive in the area's terroir.
