Grape expectations: why won't my vine produce fruit?

Freak weather in 2008 hit grape production. Photograph: robb1e/Flickr/Some rights reserved

A vine grower has taken issue with my response to a reader's query a couple of weeks back about vines that look healthy but don't flower or fruit. I blamed a lack of pruning, but Caroline Compton says:

I have half an acre of vines for wine production. In 2007 (on the Welsh border) there was no harvest due to appalling weather and the same was true of most vineyards in the UK. My vineyard was hit by freak weather this year and there have been so few grapes that there has been no harvest this year either. The weather has been the problem, not the wrong kind of pruning.

Let me know if your vines have been done in by the weather in the comments below.