Grape pruning question

[vegman]

Need a bit of advice please!

I have a large pagola with a polycarb roof between the beams. I spent the last three years growing a Black Hamburg grapevine up the the wall and under the roof for shade from the sun! I have five horizontal stems which have been stopped to desired length, each stem about 600mm apart.

I dont want it to run rampant this year but would like to stop the side shoots when about 300mm long. I would also like to make sure I get some grapes too. What should I do? But scared that I may stop before flowers appear.

In the past it sets fruit all over the place but I concentrated on producing a framework which I now have. Its time for some order now [I hope]

Many thanks in advance

Vegman

[vicky]

What I normally do is wait for the flowers to appear then stop each stem after this point - and keep it pruned back to the first truss (you have to keep retrimming every few weeks), I figure that way I get then best possible truss plus it doesn't get too rampant!
Sometimes you do have to be quite brutal as they are very vigorous!

[SimonCole]

I don't know the truth behind what some books say about them "bleeding to death" if youprine when not dormant. I know that you should do exactly as Vicky sais above and stop the laterals after one or two bunches. I would just water well and try not to chomp away too much at this time of year. I will trial cling film over the wounds this summer and see if that helps.

[TonyF]

I wouldn't use cling film, it can rot the ends off.

Just some hard pruning as you go, as Vicky said, cut back to an appropriate truss, personally I do 3rd but each to their own.

I prune our huge vine, over the pergola/terrace immediately outside the front door, really hard throughout the summer and the vine is about 18 years old and healthy as anything.

[vicky]

I think the bleeding only applies if you prune when 'the sap is rising', ie when things start to sprout in spring. Pruning new growth during the summer doesn't result in bleeding (in my experience anyway!).
I should think that the warmer the climate the more trusses will mature - which probably is why TonyF lets more trusses develop...if yours is undercover then you may get more than one per stem?