Answer: Grapes should be pruned in winter, before the sap begins to flow. If you wait until spring, the plant will "bleed" wherever you've cut it. Oozing won't hurt the plant, but it can get messy to walk under an arbor when the canes are dripping water. Grapes produce on new growth that comes from old canes. Cut the canes back, leaving two buds. These buds will produce next year's fruit. You can read about the technique in a book titled "Step by Step Guide to Pruning", by ChristopherBrickell, published Simon & Schuster. The ISBN # is 0-671-65841-7. Your library can find a copy for you. There are line-drawings and simple text to guide you through the pruning process.
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