Clipping grapevines

JoeX

Iirc youre supposed to reduce the number of grapes growing to improve quality - whats the guidance on how to do this, please?

Dovefromabove

The info you need is here 
https://www.gardenersworld.com/how-to/grow-plants/how-to-prune-grapes/
a small pair of pointy scissors are useful

Joy*

Some varieties of green grapes don't need thinning but black dessert grapes do. The idea is to give each grape room to grow to a decent size and to let air into the bunch to prevent mildew and rotting. We had special vine scissors which have short pointed blades on a fairly long handle. We also used a lolly stick with a fork cut into the end to lift the outer grapes to clip those inside the bunch. It is important not to touch the grapes with your fingers as it brushes the bloom off (the dusty looking layer) and causes the skin to develop a sort of brown scab. When you have thinned the bunch it should look a bit sparse but this will allow the grapes to swell to a good size. It is neck breaking but well worthwhile.  If you don't do it the grapes will be very small and seedy and the lack of air circulation and damp atmosphere is likely to ruin them.

JoeX

Dovefromabove said:

The info you need is here 
https://www.gardenersworld.com/how-to/grow-plants/how-to-prune-grapes/
a small pair of pointy scissors are useful

Okay, so from that Ive left it too late to prune (Dec/Jan) or cut back new growth(May), I should just be “thinning each bunch by at least half”

JoeX

Ive got five vines, this could take quite some time! 😅

Dovefromabove

You can cut back
the new growth now... I’ve been doing for a few weeks now ... my vine is outside   ...i trained the new growth vertically, tied it in and tipped it at three leaves above the support (about 6’ in this case). Today I’ve shortened the new side growth to three leaves. 

Joy*

Once you have bunches of set grapes you do cut the lateral bearing the bunch back to 2 or 3 buds so that the energy goes into making the grapes not growing lots of vine and leaves. Really you only expect dessert grapes to bear one bunch per lateral. It's an art form growing grapes which my dad taught me. Your bunches are prolific! Do you know the variety and what do you anticipate doing with them when they are ripe? If size is important to you I might be inclined to reduce the number of bunches and have fewer but bigger, better grapes.

JoeX

**One year later**

Hi all,

A follow up question - if new growth, a lateral, or whatever the correct terms is, has no grapes on it - do I cut the whole thing off or leave it for the leaves it has, or just take off the tip where the new growth is occurring?  

Ive done some overdue (again) cutting back but I’m worried that the plant is losing a lot of photosynthesis.

I think grapes are fewer this year, but it has been colder.  I’m about to get the snips out to trim the grapes themselves.

JoeX

Bump

fidgetbones

Once you have your framework, you cut off all the laterals off, two leaves after the bunch of grapes, to get light to the grapes and focus energy into them and not a lot of extra growth. You may have to cut off a lot of excess growth two or three times in the summer.  By the time the leaves fall it needs to be approaching the shape you want it, with final pruning in the winter before the sap starts rising again.

fidgetbones

If the new growth doesn't have a bunch of grapes, cut it back now.