The devastating Cudlee Creek fire in the Adelaide Hills destroyed vast swathes of local vineyards. Decades of work was destroyed in the furnace, with trellising, irrigation and machinery incinerated. Vines, too, had their trunks and cordons damaged beyond repair although with roots still in working order, many already have green shoots sprouting, suggesting they may recover. But it will take a number of years before they are back producing wine in the quantity and quality seen in recent vintages.
Henschke’s Adelaide Hills vineyard had been the pride and joy for Stephen and Prue Henschke. After the Ash Wednesday fires of 1983, which decimated the orchard on the property, the Henschke’s had created their own vine garden, with many plots for grape varieties that would be more successful than in their Eden and Barossa Valley vineyards, varieties such as grüner veltliner, pinot noir, merlot and cabernet sauvignon.
It was here that they could start from scratch and follow Prue’s principles of sustainable farming and encouraging biodiversity. Almost 40 years of work had gone into painstakingly building up the vineyard’s environmental credentials, which will take even longer than the vines to recover.
Part of the regular work in the Henschke Lenswood vineyard has been using an array of biodynamic sprays to build soil health and banning the use of synthetic herbicides and pesticides. Slashing was used in the vineyards to keep weeds at bay. The vineyards are also sprayed with biodynamic preparations every month when the moon is opposite Saturn. In addition, composts are used to build up organic matter and nutrition in the soil.
Unfortunately the Cudlee Creek fire burnt very hot through Lenswood – so hot that fence posts left no more than an eerie shadow of ash after the fire had torched them. Such fires affect not only the plant life but also the topsoil itself by destroying the organic matter and microfauna. The result is that some of the work done over decades to improve topsoil health has been erased and it will take some years before it is back to the condition it was in late last year. However, the fire’s effect on the subsoil is likely minimal with the vine roots still having access to rich and healthy soils.
Much of Prue’s work in the vineyards related to the promotion of a complex ecosystem both in and around the vineyards to assist in a variety of ways. Seven hectares on the property were native bushland, which ensured a vibrant habitat teeming with plants and animals. Throughout the vineyards there were also banks of trees and plants that created a suitable habitat for birds and insects. Stringybark forests were home to natural predators – insectivorous birds and a couple of local emus that helped to naturally keep some pests away.
The fire here left only a moonscape behind. Shrubs and grasses were wiped out leaving nothing more than black soil, exposed rocks, blackened tree stumps and shrivelled vines. The vegetation close to the soil that in some cases had been slowly coaxed to life over decades is no more, with not only plants but also seeds destroyed due to the intense heat. A key element of a vibrant ecosystem is not just having plants, but a wide and diverse range of vegetation with different flower shapes to suit a wide range of insects. Bringing back many of these species will be difficult, if not impossible, thanks to the changing climate in the Adelaide Hills. Some of the species, such as Acrotriche, are hard to propagate while others, like Yucca, are already returning.
According to Prue, full regeneration will take years. “We don’t know whether we have enough seed case to regenerate. It’s a waiting game and next spring will give us an idea. It really depends on the weather and the rainfall. It might be 10 years or it might be longer before we are back where we were.”