Japanese Cherry in July: monthly care

Prune Japanese cherry 'Kanzan' only in June or July, when the tree is in full leaf and sap is flowing freely. Pruning during the dormant winter months invites silver leaf disease and bacterial canker, both serious problems for Prunus species. The summer timing allows wounds to heal quickly and reduces infection risk significantly. This cultivar naturally forms a vase-shaped crown and requires very little pruning once established. In the first few years after planting, your main task is to establish a clear trunk and a balanced framework of branches. Remove any shoots emerging from the lower trunk, and thin out crossing or rubbing branches that will cause damage as they thicken. Always cut back to a main branch or the trunk—don't leave stubs, which invite disease. On mature trees, pruning should be minimal. Remove any dead, diseased or damaged wood as soon as you notice it, cutting back to healthy tissue. If two branches cross and rub, remove the weaker or more awkwardly placed one. You can also take out any vigorous upright shoots (water sprouts) growing from the main branches, as these spoil the tree's elegant shape and rarely flower well. Use clean, sharp secateurs for twigs and small branches up to about 2 cm diameter, and a pruning saw for anything larger. Avoid tearing the bark. For cuts over 3–4 cm, you may choose to apply a wound sealant, though this is debated; good timing and clean cuts are more important. Never top or heavily reduce a flowering cherry—it ruins the form and stresses the tree.