How to Trim Grape Vines?

[Gary350]

After 4 months my grapes have suddenly taken off growing like crazy. I have 4 plants.

Vine #1 has about 20 vines on it growing in all directions hiding in the watermelon vines. I am afraid to trim the vine now because temperature is 108 degrees now. Now I have the vines all tied up in a wad on the pole growing straight up.

Vine #2 has about 15 vines growing all directions too. Now they are all tied straight up on the pole too.

Vine #3 and #4 are still just laying there.

Do I need to wait until hot weather is over to trim the vines?

What do I need to know about trimming vines?

Am I wrong in assuming the vines need to be trimmed?

Grape trellis is 6 ft tall and 4'x10' above the ground. Vines are suppose to grow on top and grapes should hand down through the cracks.

[tomc]

Let the leaves help bulk up the roots this summer. Trim it back when its dormant in late fall early winter to the single strongest cane.

This will also be the season to build trellis.

[JONA878]

Hope that this shows the principle Gary.
There is just one long growing leader to each vine. Side shoots are allowed to grow from this. When a truss has formed on these side shoots the shoot is stopped two leaves beyond the truss. This gives a steady cropping all along the vines length.
Summer pruning is needed to keep good light falling on the vine and the fruit.

[Gary350]

What is a truss?

I built a trellis maybe I have made a mistake. I looked at photos in a wine magazine it shows vines growing 1 foot apart up to 6 feet tall. Vines are made to grow on wires, poles, bamboo, rods, cables, etc. parallel to the ground. Vine are growing 6 feet each side of each fence post.

I have about 30 vines (off shoots) to trim off of the main vine I was worried that would kill the plant it is going to be 108 degree today and 109 degrees tomorrow.

[JONA878]

A truss Gary is just another name for the forming bunch of grapes.
Your trellis is fine for your grapes.
There is no hard and fast rule for training grapes. so much depends on how much room you can allow them.
The ancient vine at Hampton Court in London is over 120 ft long and has side shoots that yield over 600 lb of fruit every year. Planted in 1769.

Providing the vine is strong it can carry a multitude of side shoots which in turn produce the cropping shoots.
As long as there is good light and the vine is healthy. let it fill the space.

Commercial growers keep the vines short to get maximum cropping of a given area and if replacement is needed there is no major loss of cropping while it grows up. Even then they use many different styles of training.

[Artemesia]

Some areas recommend early winter pruning, but in California, which I assume is similar to your location, recommends early spring. Otherwise disease can be encouraged if pruning in the early winter. For pruning technique, cane pruning is starting to gain momentum, because it removes the disease inoculum source that a cordon would provide. It is a little more difficult than cordon pruning but after time, it reduces disease.