Apart from the traditional Muscadel, Rietvallei is planted with classic noble cultivars, including Sauvignon Blanc, Chardonnay, Rhine Riesling, Chenin Blanc, Viognier, Cabernet Sauvignon, Cabernet Franc, Shiraz, Petit Verdot, Cinsaut and Tinta Barocca. The trellised vines, planted in deep fertile soils, climb up a cool southeastern slope of the Langeberg foothills where they nestle in the shade, protected against the afternoon sun.
Because of the cold winters, these vines enjoy a deep winter's sleep in the frozen earth. This winter dormancy is essential for the vines to recover, so that in summer they may produce fine, healthy grapes. When the snows melt in the spring, water from the clear mountain streams is sometimes used to irrigate the vines. Away from the pollution of the city, these vines thrive in the crisp clean Karoo air. Often, in the early morning, the vines are shrouded in mist and from the distant Indian Ocean comes a breeze to further cool the grapes, thus allowing them to ripen slowly and develop their summer sugars.
Rietvallei also boasts the oldest Red Muscadel vineyard in South Africa, planted in 1908. It is in the form of bush vines and is only about a quarter of a hectare in size.