“Coonawarra’s red terra rossa over limestone soil is a million-year-old coral reel that has literally rusted,” says Reschke. “The red soil sits like a kitchen sponge. It holds only so much water before it goes through to the porous limestone, so a vine’s roots rarely get too much water. This means we can drip feed vines to keep berries small. Smaller berries mean more skin per kilogram. Since the flavour comes from the skin, the more skin, the more flavour.”
Reschke notes that Coonawarra is the coolest region in Australia that can consistently ripen cabernet sauvignon, with Nangwarry, only a 15-minute drive south, too marginal to properly ripen the grape every vintage. “This means all Coonawarra has natural acid – anyone adding it is either crazy, or forgot they grow grapes and left it out there until June. This means Coonawarra holds more cabernet qualities than most regions, which is why it’s so easy to pick in blind tastings. Mint and blueberry are hallmark flavours.”
The Head Honcho Vineyard is a 3-hectare site on Reschke’s Koonara estate, solely devoted to cabernet sauvignon. The vines were planted in 1992 and produce small berries at very low yields of around 1 tonne per acre, with a barrel selection going to make the flagship Koonara wine, which bears the vineyard designate.
Organics are a starting point (certified since 2017), but Reschke’s approach is about constantly evolving methods to regenerate the soil, as well as to push the message to other grape-growers and farmers. “Sustainability is a bullshit word,” he declares. “Take a leap of faith and go regenerative, putting back more that you started with. When my vines started dying, it scared the shit out of me, and I started looking for answers. It came down to nutrition: like the human body, you build the nutrition so that the vine has the tools to naturally fight off disease.”
No herbicides or pesticides have been used on the property for 16 years (and that includes organic preparations), with pests largely controlled through the planting of a diverse mix of native flowers to attract predatory wasp populations. Eleven species have been recorded in the vineyards that feed off light brown apple moth and vine moth, which are real threats to neighbouring vineyards but no longer cause any issues at Koonara.
One of those species is the pin-tip-sized Trichogramma wasp that feeds on over 200 species of moth, laying its eggs inside the caterpillar eggs. This kills the nascent caterpillars, meaning the population is controlled before it can do any damage. Those wasps are so small that they stay within a 20-metre radius for their lifespan, so the vineyard has a very considered distribution of their preferred floral food source. (Butterflies have a significantly better time than moths, with what Reschke describes as a “butterfly feeder” developed to bolster the already significant regular population.)
All the flowers planted die off after producing seeds, meaning there is no water loss for the vines as they progress through to the business end of the season. Meanwhile, their root systems, which can be two to three times the size of what’s above ground, increase the organic matter in the soil, decomposing to humus. That humus holds plenty of carbon and three times its weight in water.
“We have more carbon in the soil, holding an extra 145,000 litres of water per hectare than other vineyards in the area, allowing us to water two-thirds less than the average vineyard,” Reschke says. “We build the biology in the soil to hold the carbon, which holds the water. Humus – which is 50 per cent carbon – acts like a big sponge. This means our small vineyard has pulled an extra 15,000 tonnes of CO2 out of the air so far.”
That ground cover also has a beneficial effect on the temperature amongst the vines. “We measured temperatures of bare soil versus green cover on a hot day,” notes Reschke. “Green cover was 19 degrees; bare soil was 50 degrees. You want to kill soil biology and lose ground water? Have bare soil.”
The only time Reschke mows is during periods of frost risk, where he will mow under vine every second row to maintain the biodiversity but increase wind flow to mitigate the frost risk. Then he waits for the flowers to return before mowing the alternate rows.
In terms of disease, Reschke maintains that they now have no issues, with the vines’ nutritional needs carefully monitored. That occurs through new hand-held electronic mineral analysis monitors, and somewhat more remotely through Deep Planet’s satellites, which can accurately assess the brix (sugar) levels of fruit and leaves. Keeping the leaf brix above 12 is a key component to resilience. Mineral ratios are adjusted as needed with bioavailable additions through the irrigation system. This allows Reschke to only spray twice a year, and only with seaweed, silica and calcium to strengthen the cell walls, which makes them impervious to being penetrated by mildew spores.
The nutrient density in his fruit is also making better wines, Reschke says. “It gets revealed as the wine ages. Older wines just seem to get better the more we increase nutrient density. Natural acid is also great for making age-worthy vino. Our grapes are so small with thick skins, every year the winery complains they can’t do a Baume test because there’s no juice in the bins. Not my problem – all I know is no oxygen touches my machine-picked grapes, which come in at a perfect 16 degrees ready for ferment, with no stems that can give a green flavour.”
Reschke’s approach is also very much about making a bigger impact on the global environment, with his methods freely available for all to use through his website. The benefits for vineyard owners are reduced costs, little to no disease pressure, hence little need to intervene and less time on the tractor, less diesel, less soil compaction, plus elevated fruit quality and nutrient density, which improves ferments.
“We have 30 per cent less costs than the average Coonawarra vineyard, while improving quality in the vine, and not losing tonnes,” Reschke says. “Plus, we have increased carbon in the soil by one per cent. This doesn’t sound like much, but if every farm in the world got to a total of three per cent carbon, we would take a teratonne of carbon out of the atmosphere, which is the amount that has been put there over the last 200 years.”
Reschke is even taking that mission one step further by working with supermarkets to increase the nutrient density of fruit and vegetables through improving the soil. It is his belief that beyond the obvious physical health benefits that there is likely a net benefit for mental health, and the boon for the sellers is that produce is more resilient, with a greater shelf life, saving the retailers millions of dollars.
That activism is a major part of Reschke’s process, allied with a commitment to always push the envelope with his methods. “Failure is part of life, so learn from it instead of thinking its proof there isn’t an answer, or you’re not good enough,” he says. “I’ve failed so many times I’ve lost count, but for me it’s an opportunity to learn resilience and grow. Leading people into a growth mindset is the biggest challenge. We are bringing on more farmers to help teach other farmers. It’s taught me a small vineyard can be a tipping point to massive change on this planet.”
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