The Frankland River region in the South West of Western Australia is one of the coolest and most remote wine growing regions in Australia. Mediterranean in terms of its winter/spring rainfall, it has a continental influence, with cold nights and warm days creating ideal conditions for growing quality wine grapes.
The viticultural potential of the Frankland River region was first identified by the famed botanist Baron von Mueller on one of his trips to Western Australia (1867 and 1877), followed by Californian viticulturist Dr Harold Olmo in a report to the West Australian Government in 1956, and was later endorsed by Dr John Gladstones (well-known for his pioneering work in the Margaret River region) in two reports commissioned for the Swinney family and which are the source of the material below.
Over millions of years the Frankland River has cut its way through the ancient lateritic surface rock to expose the granitic and gneissic layers beneath and has created ideal gravel-loam soils for growing quality wine grapes. These gravelly surfaces protect against erosion and warm up quickly in the spring, while the clay loam subsoil retains water during the dry summer months.
Soils include gravelly loams on the middle valley slopes, which in the natural state carry vigorous marri (commonly known as red gum) trees. They merge on the higher slopes into mixed marri / jarrah soils that are lighter-textured but still gravelly and well suited to viticulture.
The Frankland River valley also has a profound influence on the region's climate and the resultant wine styles. As a river valley draining more or less straight to the Southern Ocean the river valley has excellent water and air drainage. Cold air flows freely to the south at night, setting up an air circulation between land and sea that minimizes the risk of damaging frosts in spring. Valley-side tributaries locally reinforce this pattern by forming a series of moderately sloping ridges that are largely frost-free.
In summer the valley performs a reverse function by funneling cool and humid air northwards from the Southern Ocean. This moderates the heat of summer afternoons, and combined with ripening that extends through March into April, ensures mostly mild conditions for ripening before the first heavy rains of autumn. These ripening conditions allow very reliable production of classic cool-climate wine styles.