What is the ideal pruning height for older shrubs to rejuvenate them?

Pruning older shrubs to rejuvenate them typically involves cutting them back to a height of about 18 inches. This height is effective because it encourages the growth of new stems and fresh foliage, revitalizing the plant. By cutting back to this level, you ensure that there is a sufficient number of healthy buds remaining, which can produce strong new growth. This method encourages the plant to redirect energy towards new growth instead of maintaining old, potentially weakened stems.

Choosing a height that is significantly lower, such as 3, 6, or 12 inches, may not leave enough viable buds for regrowth, risking the shrub's health and reducing the chances of a successful rejuvenation process. Pruning at 18 inches also has the advantage of maintaining the shrub's overall shape while promoting a fuller, bushier appearance as it regrows.