What a start to winter! The Cape Winelands have been receiving good, albeit unseasonal, rain from as early as March, but June has been an exceptional month with about 200 mm of rain during the first two weeks alone. Local winemakers prefer a cold and wet winter, but can it get too wet?
Water is a treasured resource. Just recently the Cholera outbreak and Eskom-related water shortages confirmed what we knew: we can cope better without electricity than without clean, running water. Learning about the water challenges in the northern parts of the country also reminded us of the Cape draught and looming day zero that we experienced just a few years ago. In a country that often endures draughts, complaining about rain is almost sacrilege. This week, however, the downpours did cause some damage to infrastructure in Boland towns, neighbourhoods and farms. And while efforts are under way to clean-up and restore; what are the implications of exceptional wet conditions on the vine and the quality of the next vintage?
During winter, vines undergo physiological changes that help it to survive the cold. Leaves change colour and fall off slowing down the vine’s metabolism. No energy is produced through photosynthesis anymore and the plant survives on the energy it stored during the growing season. No water is absorbed during winter and the existing cell water is moved to an inter-cellular area protecting the plant from damage should this water freeze in extreme cold conditions.
The wetness of winter might not be that important to the vine during winter, but of course it is crucial for replenishing groundwater and reservoir volumes that will be required for irrigation in the growing season and warm summer months. Rain during flowering can result in the little flowers being rained off the vine and therefore fewer berries and possible disruption of the self-pollination process. We usually prefer drier conditions pre-veraison as too much water results in bigger berries, throwing off the ideal juice to skin ratio and the ultimate concentration of flavours. Rain in season can cause diseases such as mildew, but when managed well, shouldn’t be too much of a concern. Too much rain in winter can result in waterlogged vineyards, preventing oxygen from reaching the vine’s roots and ironically the vine’s ability to receive water and nutrients. Soil nutrients can also be washed away because of erosion.
The forecast is for more rain from tomorrow, but this morning, the sun is shining in the Cape Winelands and the skies are clear. This is a welcome respite for those who have to clean-up and recover, businesses can expect a return to normality and everyone who has been stuck inside, has a chance to go for a walk and perhaps even enjoy the fun of puddles. Seems we don’t have to worry too much about the effect of the rain on the quality of the 2024 vintage just yet.
- According to the Western Cape Government website, the overall dam level for the province was at 81.3% on 15 June.
- The SouthAfrican.com indicates that the six major dams in the province – the Berg River, Steenbras Lower, Steenberg Upper, Theewaterskloof, Voelvlei and Wemmershoek – are at 86.1%, up from 70.5% the previous week.
- Also click here for an interactive map indicating the various dam levels of the Western Cape.