Geography & Climate
Vines are grown along an 80km strip of the Rhône valley, which extends from Martigny to Brig. This is a glacial valley (the Valais still has many glaciers), with a relatively flat valley floor, and in many places extremely steep hillsides. Some vineyards are on slopes of as much as 70 degrees, and construction and maintenance of these are thus very labour intensive and hence costly.
Much wine here is grown at quite high altitudes; that from the valley floor and lower slopes is up to around 650m above sea level, but some comes from some of the highest vineyards in Europe, at Visperterminen in the Haut Valais, where vines thrive at altitudes of well above 1000m.
The Valais climate is very dry, often bordering on drought; in fact this part of the Rhône valley is of the driest valleys in the Alps, with the surrounding mountains preventing access by rainclouds. Summers are hot, winters and early spring cold, though tempered by the warm dry "foehn" winds blowing up from the mediterranean. A wide range of grape varieties is grown in the Valais, reflecting the varied terrain, historical isolation, a rich viticultural recent past and a vibrant winegrowing culture today.
Isolation has meant that the now rare indigenous red and white varieties (Humagne Blanche & Rouge, Petite Arvine, Amigne, Cornalin, Heida, to name but a few) have survived in commercial production. The 19th century saw the introduction of varieties such as Pinot Noir and Chasselas from elsewhere, and more recently other international varieties especially Syrah in the 1950s have been introduced.