When is the best time to prune grapevines?

Grapevine Overview

The flowering period of grape vines is from April to May, and the fruiting period is from August to September. The minimum temperature required for growth is between 12-15 degrees. The optimal growth temperature during the flowering period is about 20 degrees. The suitable growth temperature during the fruit expansion period is between 20-30 degrees. If the temperature difference between day and night is large, the coloring and sugar content will be better.

Grapevine pruning time

1. Spring pruning

Grape vines can be pruned in spring from March to April. At this time, the bud removal method can be used to remove weak buds, multiple buds, and sprouting buds, thereby reducing nutrient loss and allowing all nutrients to be supplied to the remaining buds. This is commonly known as nutrient conservation.

2. Summer pruning

Grape vines can be pruned in summer from June to July, with the fruiting branches and nutrient branches pinched off and the side branches dealt with. In addition, the bunches should be shaped, straightened, thinned, and the grains thinned out.

3. Autumn pruning

Grape vines can be pruned in autumn from September to October, and the second pinching should be done to remove dense branches, thin branches, overlapping branches, and branches with low lignification. The number of branches should be adjusted, and ventilation and lighting conditions should be improved to make the frame surface more permeable.

4. Winter pruning

Grape vines can be pruned in winter from December to January of the following year. The amount of pruning in winter is the largest and the most branches are pruned. Pruning at this time can increase the yield of the following year.

Grapevine pruning methods and steps

1. Shorten

When pruning grape vines, be careful to keep a certain distance between the place where the scissors are used and the buds. If they are too close, it will affect the growth of the buds in the next year. After that, determine the number of buds to be left based on the length of the treetops. Shorten 2 buds and choose full buds.

2. Shrinkage

Pruning is selective pruning, which is a very important job. Because old grape vines have more branches and will consume more nutrients, pruning should be carried out according to the condition of the old trees. If they are weak branches for many years, the weak branches should be cut off and the strong branches should be left for breeding. If they are strong branches, then do the opposite.

3. Thinning

That is to say, it is a rough pruning. There is a principle for rough pruning of grape vines, which is six cuts and six no cuts. Prune the weak branches and leave the strong branches, prune the broken branches and leave the complete ones, prune the distant branches and leave the nearby branches, prune the double branches and leave the single branches, prune the underdeveloped branches and leave the complete ones, and prune the old branches and leave the new branches.

Notes on grapevine pruning

When pruning grape vines, be sure to make sure the cut is flat, smooth, and free of stubble. The cut should be 1-2 cm thick to prevent the winter buds from drying out. White glue can be applied to the cut. Keep the vines in a semi-shaded, well-ventilated environment without light or watering.