If you are struggling to produce more grape clusters then you maybe pruning your grape vines incorrectly.
1. Be sure that you are pruning enough:
Most new grape growers fail because they do not prune enough. Pruning is extremely important. Pruning and training will help develop a vine structure that will aid the utilization of sunlight and help adapt to the characteristics of a particular grape variety.
Even more, pruning and training are performed in order to optimize the production potential of the grape vine. Your objective is to maintain a balance between vegetative growth and fruiting. Many grape growers find pruning and training grape vines the most gratifying of all vineyard task. You become closer with your vines individually. As with anything, the more involved you get with your grape vines the more successful you will be.
2. Give first year grape vines a chance to develop strong root systems:
Do not prune the vine during the first year of growth. Allow the vine to sprawl out as much as possible. The excess leaves and stems will allow the root system to become strong during the vines immature stage. No need to worry about winter, Mother Nature takes care of the grape vines naturally as the vines go dormant and loose all their leaves.
Understand that depending on soil fertility and grape vine variety that the growth cycle to harvest can vary substantially. In low-vigor soil conditions the final mature stage may take several additional years while high-vigor soil produces larger grape vines that may produce grape clusters in their second or third year.
3. Use A Good Positioning or Training System:
If you have ever seen grape vines growing wild the first thing you may have noticed is that they can grow and be trained to run almost on anything. Fences, trees, walls, you name it. Obviously you do not have much control over consistent growth in some of these circumstances.
VPS is the easiest and most common system used worldwide for training grape vines. VPS stands for Vertical Positioning System. With a VPS, canes are tied to the fruiting wire which is generally the first wire of your trellis system nearest the ground as they grow upwardly. Generally you have 3 catch wires located above the fruiting wire that are used to train shoots upwardly as they continue to grow. This gives the vines more sunlight and air exposure.
4. Begin with one year old nursery stock:
Never buy two year old stock from the nursery. Always stick with one year old bare rooted stock. Two year old stock is usually a sign of weakness where the first growing year is kept over until later the following year once they reach a reasonable size. Nurseries trim their vines before shipping them. However, you may consider trimming roots to an even length around 8″. This will allow your root system to be more uniform within the planting hole.
5. Know how vigorous your soil conditions and your particular grape vine variety are:
The fertility of your soil will determine how much pruning you will need to accomplish during each dormant year. You want to maintain balance between your root’s capacity with your vine’s shoot capacity. More sap flows up through the trunk into the growing shoots when the roots are well established and your soil contains high-vigor nutrients. This growth can be aided with plenty of water and proper drainage.
Conversely, if you have low-vigor soil and too little water the root system becomes weak causing your shoot growth to become weak, thus producing less grape clusters at harvest. You should aim to maintain a balance.
If your vine’s growth is weak during the previous season with vine thickness less than the diameter of a standard #2 pencil and the shoot length is less than 2 feet, then you have allowed too many shoots to grow. Leave less buds and shoots for next season’s growth to maintain balance. If vine growth is significant with canes more than 6 feet in length and diameters more then 5/8 of an inch with excessive lateral growth, then you should allow more buds and shoots to grow in order to maintain the vines balance.
Your dedication to proper grape vine pruning and vine maintenance is key to growing yourself a bountiful harvest of high quality grape clusters.