January and February are the months when the pruning of grape vines is usually done.
Pruning the vines is intended to do two things:
- Grape vines growth
- Form the shape of the vine
In mature vines, the two pruning operations coexist. In young vines, the pruning for forming the shape takes precedence.
It is proven that a vine bears fruit when it is pruned regularly (every year). That is why pruning the vine is one of the most important tasks that the gardener should do.
The flow of sap in a vineyard
As with all plants, there are two sap flows in the vine. The roots collect water and nutrients from the soil (raw sap). The raw sap rises to the leaves of the vine through the inner part of the trunk and vines.
In the leaves, with the help of the sun, photosynthesis and the carbon dioxide that the vine absorbs from the atmosphere, it is converted into processed nutrient sap. The processed nutrient sap, moves in reverse through the skin, from the leaves to the roots.
By pruning, we cut the sap pathways and stop the flow of sap as close to the root of the vine as possible. The sap flows enhance the bulb that is higher up. It is this bulb that opens and creates the burst of the new production season.
Where do we prune the grape vine?
Before I talk about where we prune the vine, we need to address some basic terms of vine morphology.
Trunk is the hard woody part of the vine that comes out of the earth. It usually forms smaller trunks called cordons. From cordons, emerge the shoots or canes. (the long, flexible branches on which the bulbs, leaves and grapes grow). By pruning to shape the new vines, we shape the direction and shape of cordons and shoots or canes.
On top of the shoots or canes are the buds, from which the new shoots will emerge in the spring. The area around each eye is swollen and is called a node. During the period when the vine is dormant, nutrients are stored in the node.
The buds on the shoots appear in opposite directions. One bud appears on the right side and the next on the left side of the shoot.
The part of the shoot between the buds is called the internode.
If we prune a shoot (cane) up to the 3rd eye, we do spur pruning and we create a head.
If we prune it between the 6th and 10th eye, we do cane pruning and we create a stray.
In general, unless there is a reason to shape the vine, we should prune vines between the 1st and 3rd eye.
How do we prune the grape vine?
Cuts should be made with a well-sharpened pruning pruner so as not to damage the vine.
It is also important that the cut is in the right direction. The cut should be away from the eye.
The correct prune cut should be away from the eye
When do we prune the grape vine?
Grape vines pruning in Greece, is done in January or by mid-February at the latest.
The crying of grape vine
The vine is crying (bleeds), when it is pruned at the right time. The “tears” are the raw sap that spills out as it does not meet any infrastructure to receive it. The phenomenon, though scientifically interpreted, never ceases to move me.
Additional very useful information
Very useful information on pruning the grape vine can be found at:
How to Prune Grape Vines – Cane and Spur Pruning Explained
Cropwatch – University of Nebraska – Lincoln, Grapes (PDF)
Grapevines Bleeding – When the Grapevine is “Bleeding” / “Crying”
