The first month of Spring is a wonderful time in the Hunter Valley with the valley slowly transforming into a bright green explosion of new growth as the new vines send out new shoots followed by rapid leaf growth. In the vineyard, it is a time of regular monitoring of late frost, and its affect on the new growth. Other risks and challenges can come in the form of overly dry weather or storms with heavy rain and winds.
The annual growth cycle of grapevines in the vineyards commence each year with budburst taking place in Spring and culminating in leaf fall in Autumn followed by Winter dormancy.
In the Hunter Valley, budburst begins around September when daily temperatures begin to exceed 10°C. Tiny buds on the vine start to swell and take the form of woolly buds. After a while (approximately 2 weeks) tiny leaves start to grow on the new shoots as the elongate – nourished by the food (carbohydrate) stored in the trunk and roots from the previous season’s growth. Eventually the tiny leaves begin the process of photosynthesis, producing the energy to accelerate growth.
There are some differences in timing of budburst depending on the varieties being grown, but sustained temperatures will initiate budburst in most vines. For example, Chardonnay always bursts relatively early whereas Cabernet Sauvignon always burst relatively late.
October is the period of rapid shoot growth (growing an average of 3cm a day) as the vine canopies fill out. New roots start yo emerge and berries become visible on the new shoots.
In November the process of flowing begins with small clusters of flowers appearing on the tips of the young shoots. A few weeks after the initial clusters appear, the flowers start to grow in size with individual flowers becoming very evident. This is the stage when self pollination and fertilisation take place. Bunches of grapes are now visible on the vine.