Marlborough:
The Region
About Marlborough
Location
Located at the northern end of New Zealand's South Island at latitude 41°30'S, the flood plain of the Wairau River covers a land area of 170 square kilometres. It is 14km wide at its eastern end where it meets the coast at Cloudy Bay, tapering to only a few kilometres at its inland extremity, 26km from the sea. The northern boundary is graphically bordered by the Richmond Ranges whose main peak, Mount Riley, features on the Cloudy Bay label. The southern boundary is equally dramatic, marked by a series of ranges, which give rise to four tributary valleys, recognised as sub-regions within the Wairau - these are the Brancott, Omaka, Waihopai, and Ben Morven Valleys.
Climate
The Wairau Valley has a cool maritime climate. Heat summation (measured in time above 10°C for the growing season) averages 1320 degree-days (1987-2004). Although the Wairau enjoys more sunlight hours than any other region of New Zealand, daily maximum temperatures rarely exceed 30°C in the hottest months, and day/night fluctuations (diurnal range) are pronounced. Spring and autumn frosts can occasionally occur and are potentially hazardous to yields and ripeness levels. The annual rainfall is 740mm and is normally spread evenly throughout the year, but it can be unpredictable. The maritime influence ensures relatively cool conditions during the growing season, allowing extended accumulation of flavour and aroma. In most years, strong westerly winds prevail throughout November and December, reducing disease pressure in the vineyards.
Soils
Geologically, New Zealand is a very young country with most rock formations having evolved in the last 300 million years. The Wairau Valley was shaped during a series of glacial periods, the last ending only 14,000 years ago. Successive flooding and re-alignment of the Wairau and other rivers of the valley have deposited glacial outwash, forming a level plain with deep, sedimentary soils varying from washed stone to gravel, alluvial silt and clay. These soils have a very good natural nutrient status. Within the deep alluvial gravels an extensive aquifer, fed by the winter snow-melt from the higher ranges, provides an invaluable resource of high quality irrigation water.
