Definition - What does Dormancy mean?
Dormancy is a part of the growth cycle of the grape vine and is a time when the vine stops the process of photosynthesis and is in a dormant state. Dormancy occurs after harvest and leaf drop when the days become shorter and the temperatures become colder, and it ends in late winter to early spring, just as the temperature increases and the days are longer.
WineFrog explains Dormancy
The annual growth cycle of the grape vine begins and ends with bud break in the spring. Bud break is the end of dormancy and the start of the new cycle of growth. A deciduous plant, grape vines cease photosynthesis during dormancy which means the vine doesn’t produce carbohydrates. Dormancy is triggered after harvest when the temperatures drop. While the grape vine lays dormant without leaves, viticulturists can inspect the vine for injury, disease or pests, and this is also the time to prune unwanted canes and old growth. Dormancy ends when the buds break in the spring and the vine begins photosynthesis again.