The viticultural year, from November 1st to October 31st, keeps pace with the seasons, and the work cycle is marked by different stages.
After harvesting, old vines are dug up. The soil is worked, ploughed or tilled to remove the broken roots and vines. The following spring, training systems are put up and new vines are planted.
This is done in the winter when the vine is in a state of dormancy. The purpose is to shape it to ensure optimum growth and to regulate the crop load. After pruning, the vine shoots are crushed.
At the end of winter, the fruit-bearing branches of long-pruned vines are bent at 90 degrees and attached to the lowest wire of the training system.
The debudding season starts end-April/ beginning-May and the operation consists in removing excess shoots. The purpose is to limit crop yield and regulate vegetative development. Also, by limiting the number of shoots and their occurrence on the trunk, debudding also enhances the sustainability of the vine, whatever the growing method used. Only six to eight shoots are preserved.
At the end of May/beginning June, once the shoots are 40 cm to 50 cm long they are attached to the wires of the support system. This is called trellising. The operation has two purposes: one is is to promote photosynthesis, which keeps the plants healthy, and the other is to enable better access between the rows of grapevines. In addition, it prevents plants from spreading along the ground, thus helping to limit the development of disease.
Once the initial clusters of buds have appeared, flowers start growing during the first half of June. During this flowering period, the pollination of the grapevine takes place, producing grape berries.
Mid-June is leaf-thinning time. This operation consists in removing spurs to lay bare the clusters and allow air to circulate around them. The aim is to enable the berries to ripen in the best conditions and stay free from disease.
From the end of June right up to harvesting, mid-August – beginning September, the tips of the shoots are cut off. This process is repeated four to five times to help promote the development of new leaves and ensure maximum photosynthesis, while maintaining sufficient leaf area for the grapes to ripen.
By the end of the fruit-set process, which happens end-June/beginning July, the grapes have started to form and it is time to green harvest. This bunch-thinning work has two specific objectives:
- To optimise ripening conditions for the remaining clusters, which will have the effect of improving the quality of the wine.
- To observe the regulations in force by limiting the load per square metre.
Veraison is the onset of ripening which starts at the beginning of August when the grapes begin to change colour and the sugar content rises. White grape varieties go from dark green to a translucent greeny yellow, and red varieties from dark green to a blackcurrant red.
During the ripening period, from end-August/beginning September until harvesting, the berries grow in size and the sugar content continues to rise as acid levels fall.
Throughout the entire vegetative process the winegrower also needs to protect the vine against all kinds of parasites and diseases such as:
- fungal diseases (mildew, oidium, botrytis or rot, etc.)
- grape caterpillars
Every disease requires specific treatment and products. Application and dosage indications have to be scrupulously observed and their effects monitored. What’s more, by scrupulously complying with the specifications of Vitiswiss (the Swiss sustainable wine-industry label), the winegrower guarantees the sustainable use of these products.
Soil maintenance practices vary according to the type of soil and their water retention capacity. The trend today is to limit the use of herbicides in favour of the managed growing of grass which is mowed two to three times in a season.