Woody plants are pruned for a number of reasons:
To maintain good health, by removing dead, diseased or damaged wood; to encourage the formation of vigorous and bushy growth; to produce plants that have a sound structure when mature; and to shape and direct growth so that plants display their decorative features to optimum effect.
Regular pruning also improves the supply of strong, young growth, which normally produces flowers and fruit in greater abundance and of better quality than does old or moribund wood.