Answer: Grapes produce fruit on new shoots that develop from old wood. You can cut back most of last year's wood, leaving at least two bud scars on each cane. This is where new fruiting wood will develop.
There are many books on the subject. If you're new to growing and pruning grapes, you may want some in-depth instructions. Try the book 'Pruning' by Christopher Brickell (ISBN#0-671-65841-7) for step by step pruning.
Grapes are quite easy to care for. Be sure they get plenty of sunlight and are watered regularly, especially during the summer months when fruits are developing and ripening. Don't fertilize or you'll get lots of rank growth at the expense of fruit.
Early spring, before growth begins, is the best time to prune your grapevines. Check out this website:
It tells you all you need to know about growing grapes and includes illustrations to guide you through pruning!
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