What is the recommended approach to pruning Nandina and Mahonia?

The recommended approach for pruning Nandina and Mahonia involves severely pruning old overgrown plants to ground level. This technique is beneficial for rejuvenating these plants when they become too large or unmanageable. By cutting them back to ground level, you encourage fresh new growth, improve airflow, and allow sunlight to penetrate into the center of the plant. This process can lead to a healthier, fuller plant with vibrant foliage.

This method is particularly effective for Nandina, which can become leggy over time, and Mahonia, which may also benefit from a refresh to promote better blooming and foliage. Severe pruning may seem drastic, but it often results in a much healthier and more appealing landscape feature. This technique can also mitigate any pest issues by removing old, potentially infected wood.

In contrast, other approaches, such as just trimming the tips of branches, might not address underlying issues related to overgrowth or leguminous growth patterns. Cutting all canes straight to the top or only pruning new growth does not provide the renewal necessary for robust growth and can leave old growth that detracts from the plant's overall vitality. Hence, the recommended method emphasizes the importance of severe cuts to regenerate the plant effectively.