What do vines consist of?
There are four key parts to a vine: Below the ground we have the roots and above the ground the trunk, arms and canes.
The Roots make up about one third of the dry weight of the vine. Some roots are from 60 cm to as much as 1,5m. Roots play a very important role in accumulating nutrient reserves during autumn.
The Trunk is the main permanent and undivided stem of the vine, which is the connecting link between the roots and the arms or main branches. The trunk increases in diameter every year.
The Arms or branches of the trunk are where the canes or spurs grow and these are pruned to produce vigorous growth for a good grape crop.
The Canes and Shoots originate each year from new buds. They begin as shoots, bear flowers and fruit, and then mature into woody canes. In winter they are pruned back in preparation for the next harvest.
Seasons of the Vines
During winter (June, July and August) the vine is dormant and uses this period to rest.
Spring (September, October and November) is a sensitive time in the vine’s annual cycle. Severe spring frosts can injure young shoots. When the vines are flowering strong winds can prevent good pollination. Cold bouts during flowering and blossoming time can also lead to poor berry set. These are all factors that affect the quality of the wine. They are among the reasons why a Sauvignon Blanc from Constantia is not the same as one from Stellenbosch, or one from Robertson.
During Summer (December, January and February) the vine needs a steady supply of both warm temperature and lots of sunshine. Heat and light create the necessary photosynthesis that produces the sugar in the grapes. When there is not enough sunshine the sugar content in the grape is low and this results in a light wine, high in acid and low in alcohol. Too much sunshine and heat and the grapes ripen too quickly and the wines are high in alcohol. Again, each factor affects the end product, the wine in your glass. There are also seasonal variations, which is why a Sauvignon Blanc from a particular region might be poor this year after being great the previous year.
Autumn (March, April and May) is a very busy time in the vineyards. By mid-April late-ripening varieties are finally brought to the crusher. By early May cover crops are planted and in June pruners remove all unwanted growth. Canes are selected, then and left for the final pruning at the end of winter.