One of Margaret River’s founding wineries, Cape Mentelle has grown from humble beginnings to be one of the nation’s most iconic producers. With the nearly 40-hectare Estate Vineyard at the heart of operations, viticulturist David Moulton has ceased the use of any synthetic products as of 2020, with a proud history of sustainable management evolving to organic practices (not certified). The Estate Vineyard is the centre of red wine production, and is responsible for Cape Mentelle’s most iconic bottlings, with their flagship cabernet sauvignon, shiraz and zinfandel all largely coming from the property’s old vines.
Cape Mentelle farm 140 hectares of vines across four sites, but the core of the operation is the Estate Vineyard in the subregion of Wallcliffe. That site was first planted by founder David Hohnen in 1970 (the estate is now owned by LVMH), with Bordeaux varieties, both red and white, shiraz and – somewhat unusually – zinfandel being planted over the next few years. That zinfandel was inspired by Hohnen’s studies in California, where the grape had somewhat of a higher profile, with the 1.15 hectares of vines now amongst Australia’s oldest.
Today, the vineyard has been progressively planted to now occupy 38 hectares. The vines are made up of cabernet sauvignon, cabernet franc, merlot, shiraz and zinfandel, with earlier plantings of sauvignon blanc and semillon having now been removed. While the younger Trinders Vineyard abuts it, and is managed in the same way, the Estate Vineyard is where Cape Mentelle’s iconic red bottlings still come from. David Moulton manages the viticulture on all sites, with organic practices implemented over the last few years.
“As of this year, we no longer use herbicides and synthetic products in order to limit as much as possible the impact of our activities on the environment and to provide a safer workplace to our staff,” says Moulton, explaining that their pest and disease strategy is based on targeted inputs of sulphur, copper and biological products, but that the development of strong soil biology and vine health and resilience are the real keys.
Parcels that go into the flagship cabernet are divided into 24 “intra-blocks”, which are “individually monitored during harvest according to stem-water potential, technological [acid, sugar etc.] and phenolic [tannin, colour etc.] maturity,” says Moulton. “This allows us to batch together sections that show complementary fruit profiles and tannin ripeness to ensure that we achieve the best expression of our site each vintage. By the time we allocate and blend, each selection becomes a part of the family, sometimes it is hard to see them separated but it does give us more options to capture our sense of place in a bottle.”
Moulton notes that one of the issues with organic viticulture can be the need for more tractor passes to monitor and manage pest, weed and disease pressure. Concerned with the diesel use, he invested in efficient tractors that have reduced fuel consumption by 10 per cent, even with more use, but he intends on taking this further still. “My wish for the next five years would be moving away from diesel, using alternative energy sources for our tractors, trucks and other vehicles.”
Across the estate’s vineyards, Moulton has also engaged a raft of technologies in the quest to focus resources accurately, as well as to identify the performance of individual sections of the vineyard to target pruning and picking decisions. This process has utilised NDVI satellite surveys and Physiocap scanning – which measures the mass, cane number and cane diameter of individual vines – to provide information about the productivity potential of the vineyard in great detail.
“By utilising precision viticulture on our estate vineyard cabernet sauvignon for the last six years,” says Moulton, as an example, “we have been able to improve our understanding of the relationship between soil and vine health. Consequently, we treat some of our micro-selections differently in terms of nutrition, cultural practices and picking dates.”
Those parcels that go into the flagship cabernet are divided into 24 “intra-blocks”, which are “individually monitored during harvest according to stem-water potential, technological [acid, sugar etc.] and phenolic [tannin, colour etc.] maturity,” says Moulton. “This allows us to batch together sections that show complementary fruit profiles and tannin ripeness to ensure that we achieve the best expression of our site each vintage. By the time we allocate and blend, each selection becomes a part of the family, sometimes it is hard to see them separated but it does give us more options to capture our sense of place in a bottle.”
Although viticulture always has its challenges, Moulton believes that their location minimises those obstacles somewhat. “Margaret River is an amazing place to grow wine grapes. Weevils and weeds can be a challenge in certain years, as we do not use herbicide or insecticide, but we do our best to study the lifecycle of the pest and incorporate cultural practices to reduce the impact.”
This process has seen Moulton establish a permanent mid-row sward, as well as working on restoring native flora in other areas. “Our vineyard interacts continuously with its environment, and this is why we are trying to strengthen positive interactions by increasing biodiversity on our site. We are currently replanting native trees and shrubs, as well as using flowering species in our cover crops to provide habitat for beneficial insects and other species. We also believe that the diversity of agricultural activities in the region is a major asset for the management of the land. As an example, we use sheep to graze our vineyard during winter – it is a win-win relation for us and the farmer.”
Moulton also notes that the long-term planning is also very much influenced by the challenges of climate change. “We are planning for the next 50 years of Cape Mentelle by utilising rootstocks, different clones and planting suitable varieties across our vineyard sites. We have reduced our water use significantly over the last five years by measuring hydric stress to determine watering regimes, as well as targeting compost application to improve the soil’s moisture-holding capacity on our leaner sections.”
While Moulton notes that there are great efficiencies in the layered use of precision agricultural tools, these measures are taken as both ecological and fruit/wine quality measures, rather than trying to automate operations. In fact, with the elimination of synthetic treatments, more manual labour is required, which now makes Cape Mentelle an even larger supporter of the local community through expanded employment.
That notion of community is an important one to Moulton, and to Margaret River winegrowers in general. “We are isolated as a region but have some incredible people that are always happy to help each other out. We have a close-knit community of viticulturists, and we all share trial information and techniques that have worked in the past,” he says, also noting that interest in their farming is now not just limited to the professionals. “Consumers have never had more access to information regarding the source of their produce, and they want to see the people that grow the grapes and to understand the entire process.”