Summer pruning is essential for ideal growth of vine (Vitis). The guide provides detailed instructions for easy implementation and provides information on everything worth knowing.

In a nutshell

  • Summer pruning required for improved berry development
  • Remove stinging shoots and shorten long tendrils
  • Defoliation is part of the annual summer care

Why summer cut of wine?

Depending on the variety, vines flower between May and July. After that, the infructescences of the (future) grapes form mainly until midsummer. Because vines are usually very fast-growing, growth can have a very negative effect on fruit development. An enormous amount of energy is put into the formation of new shoots, so that there is not enough energy left for the fruit to ripen. In addition, too dense and overhanging foliage provides shade on and in the vines. If no or too little sunlight reaches the fruit as a result, development is disrupted, they become more susceptible to diseases and pests and the crop yield decreases.

For optimal growth and good harvest yields, the grapes need a lot of light.

Best time

Summer extends from mid-June to mid-September. However, the best time for summer pruning of stinging and climbing shoots on the vine is in midsummer between the beginning of July and mid-August. An exception are long fruit shoots. These should already be "trimmed" at the beginning of June.

Summer Pruning Guide

First of all, the fruit shoots have to be cut off a few centimeters at the top. This provides a supply boost of energy and nutrients. This also benefits the infructescences on the shoots, which are stronger as a result. In addition, proceed as follows:

  • Cut off fruit shoots four to five leaves above the last infructescence
  • attach to tendrils to make increasing fruit weight bearable
  • Remove dried leaves from the fruit shoot
  • pluck dried buds
In midsummer, superfluous and energy-consuming shoots are also removed and specimens that are too long are shortened.

With these instructions, the summer cut on the wine succeeds:

  • Tear out shoots below grafts; if possible, do not cut
  • new, young green shoots break out on the lower trunk; only cut off thicker, stubborn new shoots
  • remove very long, strong stinging shoots in leaf axils
  • Break off shoots that are too close together as low as necessary
  • Excessively long fruit shoots shorten another six to eight leaves above the last infructescence
  • cut dried tendrils back into the healthy tissue - if necessary up to the base
  • Break out stunted shoots and water shoots

Tip: Basically, breaking out shoots is a better approach than cutting them off. By breaking out, no new shoot grows at the point, which is significantly more advantageous for the further growth of the grapes.

Sort out grapes

In order to save uselessly wasted energy, it also makes sense to sort out certain grapes. This includes those that are far behind the contemporary stage of development of the other fruits, as well as withered, stunted, mushy, damaged by birds or pests, or simply weak growth forms. Here are some things to keep in mind:

  • always use disinfected cutting tools
  • Ideal case: pull off the grapes with their stalks
  • if there is rot or other visible damage to the fruit, look closely at neighboring grapes and remove them if necessary

Tip: Always pick up fallen grapes from the ground quickly. Not only can they attract pests, they can also cause life-threatening symptoms of poisoning in pets after consumption.

Defoliate

In addition to cutting off various shoots and shoot tips, defoliation follows. This is an important task so that enough sun reaches the fruits and they can grow strong and healthy. If they are completely in the shade of leaves, moisture is retained better underneath, which promotes fungal infections and, above all, gray mold and offers optimal “breeding ground” for pests. The following instructions describe how defoliation works properly and what to watch out for:

  • Defoliate over a period of two to three weeks to avoid sunburn on "shade bunches".
  • defoliate late-ripening varieties particularly slowly on sunny southern sides
  • Remove leaves around grape zones piece by piece
  • Also remove the stems
  • leave some shady leaves as sun protection
  • pay attention to uniform light conditions of the vines so that all grapes reach harvest maturity at the same time

Tip: The defoliation is carried out in midsummer, but a glance during the flowering period and especially when the first fruit is formed allows obscuring foliage to be recognized early and removed. This reduces the risk of many developmental defects and grapes going bad.

size correction

If a vine appears at an undesirable height and/or width in summer, the summer pruning can also be carried out to correct it to the desired height and width. However, fruits form from the second or third year of planting. If you cut back in summer, there is a high risk of cutting off fruit buds, infructescence and/or unripe grapes. Therefore, some details should be considered:

  • ideal: correct early-ripening varieties in height/width in midsummer after harvesting in June
  • Only cut back the height and width of late varieties in an “emergency”, for example if tendrils damage gutters or facades
  • Height and width corrections, if too many grapes disturb the growth, then cut off lateral and high-growing grapevines including shoots
  • Vines severely weakened by disease or pest infestation: pruning possible at any time of the year when there is no frost

frequently asked Questions

When should young vines be pruned in summer?

In the first year of planting, young vines need sufficient time to root, to establish themselves and to reduce the stress caused by the change of location. A summer cut in the same year would therefore mean renewed stress and, in the worst case, disturb the acclimatization. Only a training cut in the first fall is advisable, through which the shape and size can be "trained" at a young age. Summer cuts on the wine should only be made from the second or third year of life.

Can pruning be done in summer?

No. Pruning is about reducing the wood formation on the plants. For this purpose, pruning must be carried out outside the active growing season. The best time for pruning is therefore between February and March. The summer pruning is mainly characterized by fruit optimization and a lush harvest of aromatic grapes.

What to do when a lot of grapes grow, but they are very small?

The cause is often the rich amount of grapes. If a large number of grapes grow, the plant can usually not supply them all equally. Existing supplies are to be shared among all, which leads to an undersupply and correspondingly underdeveloped, small grapes. Here you can only reduce the stock and remove grapes as part of the summer pruning. The plant tolerates up to a residual stock of 30 percent. The remaining fruit should grow faster afterwards.

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