Although I have lived in the Barossa since the early eighties, I was fortunate enough to purchase my property in the Barossa Ranges in 1994.
At a little over seven acres and at 1,800 ft above sea level, I have immensely enjoyed the time it has taken to restore the Shiraz vineyard, which was planted in 1910. It took me 10 years of pruning and re-trellising to get the ancient vines back into sustainable shape.
Because we have never had Phylloxera in South Australia, thanks to a 120 year quarantine by the wine industry funded Phylloxera board, the vines survive on their own roots. This enables them to attain a great age, while still remaining productive. As the most senior vines begin to decline, they are rejuvenated with younger growth material through the ancient technique of layering. Thus, the original root systems are maintained.
Why are old vines better? It is simply because they have survived in the same environment for so many seasons. They have become harmonious with their surroundings and strongly resilient to the swings of seasonal change. The roots extend deep into the underlying decomposed podzolic clay, which stores moisture during the Summer Months, eliminating the need for irrigation. In addition, the pond at the bottom of the vineyard acts as a passive water source, supplying the underlying soil strata with moisture. The pond is also a superb yabby dam (think Crawfish with nippers), which provide a delicious annual feast for my grape pickers. It's also home to a considerable population of frogs, which keep me awake on Summer nights.
The soil map shows that the property lies at the transition of two soil types. The Southern, North-East facing hillside is where the vineyard is located. It is a very sheltered site, well protected from Southerly storms. The underlying soils are the result of weathered rock from the Paleozoic age, some 500-250 million years ago. We believe that there was a semi-tropical rainforest at this location around 40 million years ago, hence the underlying, acidic, podzolic clays, which nurture the vine roots. Thus, it goes to show that what went on millions of years ago has direct impact on what we see today. The average annual rainfall is around 750mm, although the past few seasons have been unusually dry. It might sound a bit cliché, but, just like the watch advert, you never really own an ancient Shiraz vineyard, you are merely it's custodian for the next generation.
To sustainably manage the vines, less is better. I don't disturb the soil with tillage. I prune the vines hard and feed them gently during the growing season with a spray of natural nutrients. As soon as the grapes begin to colour, the entire vineyard is covered with bird net, to prevent damage to the fruit and to enable it to achieve full ripeness in pristine condition.