Can a Japanese Maple Tree Be Pruned When in Bloom?

Japanese maples are famous for the beautiful foliage and shape.

Unless it is absolutely necessary, you shouldn't prune a Japanese maple when it's in bloom. To ensure a healthy, beautiful bloom and foliage, it is best to prune the tree when it is dormant. Pruning the tree when it is in bloom will sap the tree of vitality.

Bloom

Japanese maples "bloom" in late spring. They don't have flowers, but they do bud and produce richly colored foliage.

Opinion of Royal Horticulture Society

According to the Royal Horticulture Society, a Japanese maple is best pruned when fully dormant (November to early February) "as maples bleed sap from pruning cuts at other times, weakening the tree."

Avoiding Sap Bleed

Most gardeners warn not to prune the tree in late spring, as this is the season sap is rising and, according to The Weedy Reader, "all the plant's energy is devoted to the emergence and development of the young leaves."

Prior to Bud Swell

In line with the advice above, do any substantial pruning in the cold months prior to bud swell. The website "Japanese Maples" recommends that pruning be done in late summer or early fall.

Advice on Pruning

It is best to prune your Japanese maple in the winter months, when the branches are bare, to better spot and remove stems that appear below a graft or sucker shoots at the base of the tree. Cut just above a live bud or just in front of the collar (the small ridge where a branch attaches to another). Don't prune to achieve the "right" shape: a Japanese maple will grow into a beautiful shape naturally, requiring very little in the way of pruning for shape. Prune to clean, not to control.

References

• Royal Horticulture Society: Japanese Maple
• The Weedy Reader: Pruning Japanese Maples
• Japanese Maples: Fall is a time of great opportunities