Mid Glamorgan,
United Kingdom 
I have a black hambourg grape vine which has produced good crops for the last 15 years which I prune each winter. It suffered with a mould infection three years ago and since has not flowered for the last two seasons and it seems to have lost its vigour. Should I remove it or give it one more chance ?
15 Jan, 2010
Prune hard back, take the whole rod/rods down to ground level, also canes if you have some new growth on the end. Dust the whole area with Bordeaux Mixture, paint the rods with a solution of the same. Feed with Blood, Fish and Bone in early March, at the same time as you can see new buds developing, disbud if they are coming thick at different unions, put back into it's growing position, spray again with Bordeaux Mixture. Don't overcrop.
15 Jan, 2010