How to prune black walnut

Late winter (dormant, before bud swell) in dry conditions — typically late January to early March. For young trees, prune annually to establish a central leader and evenly spaced laterals. For mature trees, prune every 2–3 years to remove dead, diseased, or crowded branches and open the canopy. Sterilise tools with 70% alcohol or 10% bleach solution, and avoid pruning in wet weather.

Annually for young trees; every 2–3 years for mature trees. Black Walnut needs pruning when young to establish a strong central leader and well-spaced scaffold, and periodically as a mature tree to remove dead or crossing wood and improve airflow. Prune in late winter dormancy in dry weather — fresh wounds are infection courts for fungal pathogens and walnut blight bacteria. Limit removal to 20% of the crown per season.

For young trees, prune annually to establish a central leader and evenly spaced laterals. For mature trees, prune every 2–3 years to remove dead, diseased, or crowded branches and open the canopy. Sterilise tools with 70% alcohol or 10% bleach solution, and avoid pruning in wet weather.