Pruning Japanese maples between late autumn and mid-winter, from November through to January, is the best way to keep the tree healthy and "more beautiful", according to gardening expert Jessica Walliser from Savvy Gardening.
Walliser warned that incorrect pruning can "destroy their beautiful shape and foliage", and stressed that timing is crucial. She explained: "The best time of year to prune any living wood is late autumn to mid-winter (November through to January). I don't prune my Japanese maple any time after January."
Why late-winter pruning is risky
Unlike most other deciduous trees, which can be cut back during their dormant period, maples should not be pruned in late winter. Walliser noted: "If pruning occurs in late winter, the wounds weep sap."
While this will not damage the tree, it could attract insects, and the pruning wounds may remain open longer, increasing the risk of disease exposure.
How to approach the pruning
Determining when to prune Japanese maples can be challenging, especially since spring and summer cutting should be avoided. The first step is to remove any dead wood, which is most commonly found on the lower side of the tree. It is essential to check the underside thoroughly, as this is typically where most deadwood accumulates.
Any new growth that does not complement the rest of the tree's development should be trimmed back to maintain its distinctive shape. However, Walliser advised that side branches extending a considerable distance from the trunk should only be cut away "unless it is absolutely necessary", as they are "much better off growing to their natural form."
