Rusty Hinge wrote in message ...
The message
from (billtheburglar) contains these words:

my grapes are turning themselves into raisins, as you can see here
http://myweb.tiscali.co.uk/rleigh/index.html. It is a 4 year old black
hamburgh and produced four good bunches last year. The vine grows
along the ridge of an unheated greenhouse. It may be too close to the
glass and I might be overcropping it a bit. help please!

They aren't raisins, they're rotting.

A four year old Black Hamburg ought to be carrying more than four bunches.

1) Do you know when to prune?
2) do you know how to prune?
3) are the roots inside or outside the greenhouse?
4) have you any ventilation, and if so, do you use it? (The best way is
to have two roof-lights, one of which opened automatically with a
bi-metal strip.)
5) what fertiliser (if any) are you using?
6) Have you noticed any grey mould on the vine or elsewhere in the greenhouse?

Thank you for the response. 1 yes 2 yes 3 inside 4 yes and yes 5
manure water plus tomato feed 6 no

The grapes aren't rotting - the effect really is quite raisin like to
look at - ie they are drying up and mummifying

After some further googling I have discovered this page on the RHS
website: http://www.rhs.org.uk/advice/profile...e_shanking.asp

and am 900% confident that shanking is the problem both from their
photo and description (both well worth looking at)

Many thanks for your help