This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
You cannot think too much in the direction you name. It is folly to think that improvement is not possible. Let us have no stereotyped editions of gardening affairs.
Remove the musk and destroy as many of the borer as you can find. Large foliage on Vines - as in your case - is not always accompanied with superior or abundant crops of Grapes. There is, however, no reason why you should not have good crops. We suspect the roots of your Vines are sinking far from the surface of the border, and that the wood has not been well ripened. If you raise the roots, put them into good soil, not over rich, and ripen the wood thoroughly; it will remedy the evil.
Your Vines have doubtless suffered from the wet adhesive state of the border, aggravated by the sunless season experienced in Scotland. You will never have satisfactory results until you lift and replant the Vines in proper soil - a good holding loam lying on perfect drainage.