Walnut trees are very simple to grow and require little maintenance. That includes rarely needing pruning, though when they do there are two key rules to follow. Prune walnut trees from midsummer ...

Pruning is an essential part of any tree maintenance ... Birch trees, maple trees, and walnut trees all bleed sap heavily when pruned in winter, so can be pruned in mid-to-late summer.

Don't prune in early spring, as many trees bleed sap if cut at this time of year. The exceptions to the 'deciduous tree' rule are maple, horse chestnut, birch, walnut and cherry trees which all ...