Greenhouse Grapes

[JayTee]

Can anyone help, for the last 7-8 I've been growing Black Hamburg grapes in my tunnel and greenhouse, these were cuttings taken from a friends vine, the roots are both planted inside, the tunnel and greenhouse are around 10 mtrs apart, both produce a large crop but the ones in the greenhouse have never ripened and always remain bitter where as the ones in the tunnel are always lovely and sweet, any ideas

[nickdub]

does the PT get more sun than the GH ?

[JayTee]

Both get full sun all day Nic

[bario1]

Do vines prefer a more humid environment maybe?

[nickdub]

Could it be a disease of some kind affecting one vine ?

[JayTee]

The vine looks healthy to me, if I could figure out how to add photos I'd post a shot of the vine

[Scarlet]

I’m sorry but you don’t have enough posts under your belt yet to upload photos....keep talking just over half a dozen to go

I don’t know much about grapes but I remember reading a blog sometime ago and it may explain ( or confuse things )

Due to genetic instability, most of the older grape varieties have a tendency to mutate, adjusting to their location, climate, terrain, etc even from a clone/cutting from the same plant. Each plant has different tastes.
Taken from this blog:
http://arrowheadwine.blogspot.com/20...osses.html?m=1

It’s really interesting and worth a read.

[nickdub]

The vine looks healthy to me, if I could figure out how to add photos I'd post a shot of the vine

I'm out of ideas on what might be causing the problem, but if I was in your shoes I think I'd take a few cuttings from the good vine over winter, with a view to replacing the non-performing one if it doesn't buck up next year.

[Paulie]

I'm out of ideas on what might be causing the problem, but if I was in your shoes I think I'd take a few cuttings from the good vine over winter, with a view to replacing the non-performing one if it doesn't buck up next year.

I agree, best to take scuffing from the good one. If it turns out the same in your greenhouse, you can then conclude that the environment is the cause.

[JayTee]

I agree, best to take scuffing from the good one. If it turns out the same in your greenhouse, you can then conclude that the environment is the cause.

Yes I've already taken cuttings also there was young vine in the tunnel that must have started from a seed from a fallen grape which I'll grow on, thanks for your help