Equinox, Bud Burst & Spring Wines
In the northern hemisphere the spring equinox on the 20th March marks the official start of our astronomical spring. This balance of longer days and shorter nights pushes bud burst along in our wine growing regions and with rising temperatures, awakening vines are the order of the day.
You might imagine, that after the grapes are harvested in the autumn, wine farmers spend the winter months lazing on the sofa watching Netflix. But, relaxing and forgetting about their vineyards until the spring is not an option as there are a series of jobs the grape grower sets in motion once their wine fermentations are safely underway.
As with any keen gardener, starting in the autumn, the end of season weeding and fertilising gets tackled along with a general vineyard tidy. This tidying is important to avoid undesirable fungal spores and pests or diseases overwintering in vineyard detritus.
Then, after the vines change colour and the leafs fall to the vineyard floor, the vine can enjoy a period of dormancy over the winter months. Pruning begins in earnest in January and February with as much as 90% of the old wood being removed ready for spring.
The March equinox marks the beginning of spring. The vines tiny brown buds slowly start to open on the bare wooden canes, unfurling tiny fuzzy leafs, an impossibly beautiful shade of green and delicate beyond imagination.This phase of grape growing is only the start of the years hoping, praying and worrying for the grape farmers in the grape growing season ahead.
Entering April and the buds open more fully and the biggest concern is usually frost. Potentially devastating after bud break, these weather events often occur in a limited way every year, but they have, in the recent past, had fatal consequences for many Northern Hemisphere wine regions.
In late April 2016 and 2017 plus in May 2017 severe frost hit vineyards in Europe with some estates reporting losses between 50% to 100%. France, Germany, Italy, Spain, Switzerland and England all saw new buds perish, the loss was compared to the 1981 and 1991 frosts.
Depending on budget, action can be taken to mitigate losses, but with severe frosts, the efficacy can be limited as was the case in 2020 in some German wine regions. In Burgundy small vineyard stoves are used as the hot air can prevent a frost forming on the buds. Wind machines can also be used in wine regions where the fans move the air to prevent frost and with a bigger budget the fanning can come from a helicopter. The use of sprinklers can also prevent frost forming depending of the type of frost.
Climate change comes into play when mild March weather and early and advancing bud break has resulted in vines being too developed when the frosts strike. In these cases the consequences are so severe that the vines can't recover to produce a successful harvest that year and it also impacts the following years bud development as they are formed this year.
So for 2021, lets welcome the spring equinox, the warmer weather, the longer days and grant the vines enough cool weather early on to keep those buds small and tight. Let them make it through the spring, unscathed, and above all lets hope for no late unseasonal frost.
Wines to enjoy at this times of year include Marlborough Sauvignon Blanc, Galician Albarino, Austrian Gruner Veltliner and Vinho Verde from Portugal. For reds look for lighter styles such as Beaujolais, Bardolino and Pinot Noir.