South Africa's wine regions — from the granite soils of Swartland to the historic slopes of Constantia and the valley floors of Stellenbosch and Paarl — are facing a new and urgent reality. Hotter springs, compressed harvest windows and persistent water shortages are no longer distant projections; they are the conditions growers are managing right now. Understanding the tools available — alternative cultivars, carefully matched rootstocks, industry demonstration programmes and block-level data systems — is the first step towards making sound, long-term replanting decisions.

What the Data Is Already Telling Us

The Vinpro Technical Harvest Report 2026 is available on the Vinpro Portal and provides a sobering baseline for vineyard planning [2]. According to the report, rainfall from December to the end of February was 50% below the long-term average [1]. Total rainfall during the winter months was approximately 20% below the long-term average, with conditions becoming extremely dry from July onwards [1]. Spring temperatures were about 1°C to 3°C warmer than normal, and some vineyard blocks reached bud break one to two weeks earlier than usual [1].

In parts of the Klein Karoo, particularly around Ladismith, irrigation water was severely limited during the 2025/26 season [1]. These are not anomalies to be managed around — they are the new baseline against which every replanting decision must be evaluated.

A study published in the South African Journal of Oenology and Viticulture reinforces this picture, noting that many South African wine-growing regions already receive too little rainfall to meet grapevine water needs, making irrigation a critical part of production [1]. The same study recommends improved water-use efficiency, revised irrigation strategies and careful selection of cultivars and rootstocks as the primary levers available to producers [1].

Alternative Cultivars Under the Spotlight

The search for drought-tolerant, heat-resilient cultivars has accelerated considerably. Varieties such as Assyrtiko, Nero d'Avola and Xinomavro — native to the hot, dry conditions of the Greek islands, Sicily and northern Greece respectively — are attracting serious interest from South African viticulturalists. Their adaptation to low-water, high-temperature environments makes them logical candidates for regions where traditional Chenin Blanc or Cabernet Sauvignon blocks are under increasing stress.

The industry's GEN-Z Vineyard Project, which has since evolved into the Advancement of Viticulture Collective (ADVICO), uses demonstration sites to test cultivars, clones, rootstocks and vineyard practices under real farming conditions [1]. These trials reflect a broader industry shift: rather than waiting for long-term academic research to filter through, producers are putting alternative cultivars into the ground under real farming conditions to generate practical, site-specific data as quickly as possible.

For a producer in Paarl or Stellenbosch considering a replanting programme, these demonstration sites represent a critical early-stage data source. Watching how Assyrtiko performs on a specific rootstock in the Swartland, or how Nero d'Avola handles a clay-rich Paarl soil, is far more actionable than laboratory projections alone.

Rootstock Selection: The Invisible Architecture

Cultivar choice attracts most of the attention, but rootstock selection may be equally decisive for long-term resilience. The right rootstock influences water uptake, drought tolerance, vigour, and the vine's ability to maintain productivity under heat stress. Winetech has funded research into drought-tolerant rootstock options, and Vinpro has worked with producers on soil and vineyard management approaches that integrate rootstock performance data.

When planning a replanting programme, producers should be asking: which rootstock combinations are being trialled alongside the alternative cultivars at ADVICO demonstration sites? How does a given rootstock perform on the decomposed granite of Swartland versus the heavier alluvial soils of Constantia? These are block-level questions that require block-level answers — which is precisely why demonstration sites matter so much.

ADVICO: Turning Research Into Real-World Results

The industry's GEN-Z Vineyard Project has evolved into the Advancement of Viticulture Collective, known as ADVICO [1]. According to explain.co.za (September 2026), ADVICO is actively running climate-adaptation demonstration sites, with its current focus including climate adaptation, efficient resource use and finding cultivars and rootstocks suited to changing conditions [1].

The demonstration-site model is significant because it closes the gap between published research and farm-level decision-making. A grower in Stellenbosch can observe how a specific Assyrtiko clone performs on a specific rootstock in a comparable climate zone, under actual South African farming conditions, rather than relying solely on European or Australian analogues. ADVICO's sites are not static display gardens — they are working vineyards generating season-by-season performance data that feeds directly into Wine of Origin (W.O.) planning and SAWIS reporting frameworks.

For producers considering replanting, engaging with ADVICO's demonstration findings before finalising variety and rootstock selections is a practical step that can significantly reduce the risk of costly mismatches between plant material and site conditions.

Building a Decision Framework for Replanting

Faced with accelerating heat stress and water restrictions, vineyard managers need a structured approach to replanting decisions. A sound framework typically moves through four stages:

Site characterisation.** Before selecting a cultivar or rootstock, document the block's soil profile, water-holding capacity, historic irrigation demand and microclimate data. Blocks within the same farm in Paarl or Stellenbosch can behave very differently.

Climate trajectory assessment.** Use the Vinpro Technical Harvest Report data as a benchmark. The report recorded rainfall from December to the end of February at 50% below the long-term average, and spring temperatures about 1°C to 3°C warmer than normal — plan for that trajectory to continue rather than normalise [1].

Cultivar and rootstock shortlisting.** Cross-reference ADVICO demonstration site findings with the performance data being generated under real South African farming conditions. Prioritise cultivar–rootstock combinations that have shown actual performance in comparable South African conditions.

Ongoing block-level tracking.** Replanting is a multi-decade commitment. Once new plant material is in the ground, systematic season-by-season recording of phenology, irrigation consumption, disease pressure and yield per block is essential for evaluating whether the selection is performing as expected — and for informing the next round of decisions.

This is where winery management software becomes a practical tool rather than a back-office convenience. Cepaos, for example, records block and parcel data including phenology milestones, field work orders, phytosanitary applications and harvest records, allowing managers to build a multi-season performance picture at the block level. When SAWIS declarations and cellar records are integrated into the same system, the traceability chain from vineyard decision through to Wine of Origin compliance is continuous and auditable.

Supporting the Smaller Producer

It is worth acknowledging that the replanting challenge falls unevenly across the industry. Larger estates in Stellenbosch and Paarl may have the capital to fund nursery partnerships and rapid replanting programmes. Smaller and emerging producers — many of whom are in exactly the regions most exposed to drought and heat — face the same agronomic pressures with fewer resources.

The Western Cape has had a dedicated climate response framework for agriculture since 2016, the SmartAgri Plan, developed with the University of Cape Town's African Climate and Development Initiative [1]. Government support programmes such as the Comprehensive Agricultural Support Programme (CASP) can provide eligible farmers with infrastructure, irrigation rehabilitation, production inputs and technical advisory services. VinPro has reported that more than 50 new entrants received almost R100 million in development support over a decade, including infrastructure, movable assets and other capital needs — evidence that industry-government partnerships can reach emerging producers, even if access remains uneven [1].

For smaller producers navigating these options, alignment with IPW (Integrated Production of Wine) and WIETA standards — and the record-keeping they require — is both a compliance obligation and a practical asset when applying for support programmes.

Climate-adaptive viticulture in South Africa is no longer a niche research topic. It is the central operational challenge for every grower planning a replanting programme in the coming seasons. ADVICO's demonstration network, and the season-by-season data being generated across Stellenbosch, Paarl, Swartland and Constantia are building the evidence base the industry needs — but only producers who capture and analyse their own block-level data will be positioned to act on it decisively.

If you want to bring that block-level discipline into your own operation, explore what Cepaos can do for your winery.

Sources

South Africa’s wine farms face a climate change test — explain.co.za, published 15 days ago. https://explain.co.za/2026/09/29/the-government-is-helping-wine-farms-face-climate-change-is-it-enough/
Reports | Vinpro Portal — portal.vinpro.co.za, accessed 14 October 2026. https://portal.vinpro.co.za/category/reports/