 Flowering occurs when average daily temperatures stay between 15–20 °C (59–68 °F) which in the Northern Hemisphere wine regions is generally around May and for the Southern Hemisphere regions around November.A few weeks after the initial clusters appear, the flowers start to grow in size with individual flowers becoming observable.It is during this stage of flowering that the pollination and fertilization of the grapevine takes place with the resulting product being a grape berry, containing 1-4 seeds.