The soil from which our region grows

The region’s geology is dated as perhaps the oldest of the earth’s viticultural regions, surpassing South Africa and Europe, with its granite and gneiss rocks aged between 1,130 and 1,600 million years old.

The land as we see it today is a result of global tectonic events that began in the Jurassic period. These tectonic events formed a deep linear trough of sedimentary rocks in the east while an iron-rich lateritic plateau formed in the west, separated by the Dunsborough faultline. Since then, the soil types have mixed and merged across the landscape. Today, the soil profiles of the region are like two patchwork quilts sewn together in the middle with a large stitch representing the Dunsborough ridge.

Uniquely, ten major soil types have been identified in the Margaret River Region ranging from deep, infertile sands to shallow, gravelly soils. The more gravel-dense soils occur down the centre of the region from north to south and in the west while the sandier soils are found in the east. The amount of gravel in the soil depends on proximity to the ironstone ridge which underlies most of the shallower soils of the region.  

There is no denying that this ancient geology makes for a fascinating history as well as an impressive landscape, but the soil composition of the region is also the reason it can produce such distinguished wine as well as gourmet, fresh produce. While the gravelly, moderately fertile soils along the ironstone ridge are ideal for viticulture, the softer, sandier soil types make a great base upon which farmers can build their verdant gardens.  

When it comes to wine, the star of the show in terms of soil type is Ironstone Gravels, known locally as Forest Grove soils. They make up the highest percentage of vineyard area at 45% and are not found anywhere else on Earth. As a result, they are often credited for Margaret River’s success as a wine-producing region.  

Domaine Naturaliste Winemaker, Bruce Dukes, writes, “These soils… have good drainage and only moderate water holding capacity which perfectly suits the requirements of the vines.” In addition, the high gravel content helps to retain heat assisting with ripening. This unique combination of low vine vigour and optimal ripening conditions bestows the wines unparalleled intensity and concentration, both crucial for producing wines of distinction, year after year.

While each winemaker has their preference when matching wine variety to soil type, they will all generally agree that the local soils have a positive effect on their wines. Some prefer the Forest Grove soils for crafting iconic Cabernet Sauvignons and the sandier soils for producing the beloved Gingin clone of Chardonnay. In this way, the diversity of soil types in the region becomes its superpower, meaning winemakers can mix and match different varieties to different soil types, each soil profile providing its distinct imprint on the wine.

Jacopo Dalli Cani, Winemaker at McHenry Hohnen, shares his insights, writing wines made from sandier soils “tend to be ethereal and floral… medium-bodied and fragrant, with a distinctive savouriness”. In comparison, a vineyard with higher gravel content yields wines ‘that are fleshier, with more upfront texture, and generally a higher tannin profile for reds.”

While some winemakers might take you straight to a tasting at their landmark cellar door, Scott and Annette Baxter first draw context from Gralyn Estate itself: almost 200 hectares of pristine pasture and forest, and just ten hectares under vine.

Regionally, soil types differ, however Gralyn is fortunate to be located on the high slopes of the famed Wilyabrup Valley. The site consists of a gravelly loam topsoil with clay subsoil about a metre down. The clay subsoil acts like a sponge, soaking up winter rains and sustaining the dry grown 1975 plantings through the long dry growing period between November and March.

“The Margaret River Region has this lovely Mediterranean style climate, not too hot, cold, wet or dry. The Gralyn vineyard is located 2.5km from the coast, so the Indian Ocean and Leeuwin current play a major role in shaping our successful vintages. It’s this proximity to the ocean and unique elevation that moderates our vineyard soil temperatures, enabling fruit to ripen to full maturity without extreme variation. A cooling sea breeze on a hot summer afternoon can reduce the temperature in the vineyard by as much as ten degrees.” Scott says.

Just a short three-minute drive from Gralyn Estate, Evans & Tate is beautifully placed off Metricup Road. Senior Winemaker Matt Byrne agrees it is the proximity to the ocean, soil consistency and perfect seasonal temperatures that contribute to the overall excellence of the region’s wines.

Soil and the right conditions earned Evans & Tate’s ‘2021 Redbrook Estate Chardonnay’ an astounding three trophies and crowned Wine of Show, Best White and Best Chardonnay at the Sydney Royal Wine Show 2023.

“Australian Chardonnays are at the top of their game and the Evans & Tate Redbrook Estate Chardonnay is delivering the highest quality at an accessible price for this level of wine,” said Chair of Judges Sarah Crowe.

When it comes to soil types for growing gourmet produce, the focus is on finding the right patch of earth and building from there. Mario Lannarelli of Mario’s Garden Karridale writes, “The soils of Margaret River, you must build them as the soils in Australia are depleted of most nutrients. We’ve got some good soils, but you need to find the right spot where there is no rock, so you can plant.” This may be difficult, but Mario adds, “If you look after the soils, then the soils transfer it to the fruit you grow.” 

To understand the full picture of Margaret River’s agricultural prowess, one cannot simply look at the soil types in isolation. It is the combination of climate and soils that sets this region apart in terms of high-quality wine and produce. As Bruce Dukes writes, “These beautiful soils and the soft maritime climate create ‘Goldilocks’ conditions’”. 

Speaking of his garden in Augusta, Steve Wood from Wood’s Cottage Nursery states, ‘We have this unique micro-climate that is driven by the two oceans and the Blackwood River… it means that the temperature rarely goes below 10 degrees, rarely goes above 30 degrees, which creates a ‘Goldilocks’ zone, it is the perfect zone for growing.’ Whether grapevines, fruit, vegetables, hops, or olives, the combination of ancient, diverse soils and a mild maritime climate makes the Margaret River Region the ultimate cornucopia. 

To sample the unique imprint of the region’s soil profiles on the local wines, stop in at one of the many Margaret River Wine Region cellar doors. There are almost 100 to choose from! 

To peruse the local fruit, vegetables, produce and products head to the Margaret River Farmers’ Market every Saturday, Western Growers Fresh and Origins Market in Busselton, and the region’s other local markets.