In article , Chris Boulby
writes

I hear what you are saying Alan, and I fully agree that you will get a
poor crop if they are not grown under glass in many parts of the UK, but
it is the lack of summer sunshine and heat rather than winter cold and
damp that prevents them from doing well. Are there any known to be
tender in this regard?

The one I grew in S. Yorks was a German red grape and it had good sized
berries on it, sorry I don't know its name now. But I would obviously
have got a better crop if the foliage part of the plant had been kept
under glass (or polytunnel).

This is an interesting point. We crop Black Hamburgh, Madeliene Sylvaner
and Blaue Traube (?) very well in our greenhouse. The last was given to
us by some German friends from Konigswinter who were sure it would do
well outside because it does so in regions of Germany further North than
we are on the south bank of the river Humber. It is similar to Black
Hamburgh, but with slightly smaller, redder and earlier fruit.

Within a few feet of that greenhouse is an older, partly dismantled and
de-glazed greenhouse where we grew Black Hamburgh and the German grape
for years. The vines still grow very well there, but even in last year's
summer, no bunches matured to edibility. My feeling is that height above
sea level could be a factor. Northern European vines seem to do well on
high ground, but we are only a few feel above sea level and that could
make the difference.
--
Alan & Joan Gould - North Lincs.