Japanese Maple Pruning

Supplement to Swanson’s Seminar “Pruning Japanese Maples”

Pruning the beautiful and delicate-looking Japanese Maple (Acer palmatum, A. japonicum, A. shirasawanum & others) may be intimidating at first. But by following a few logical steps, you can reduce some of the mystery and make your tree healthy and beautiful for years to come. Here are some basics of the science and art of Japanese Maple pruning.

WHY PRUNE JAPANESE MAPLES?

Redirect growth energy (not slow or stop it).
Reveal beauty (not create it).
Improve health; allow greater access to air and light — help it “breathe.”

WHEN TO PRUNE THEM?

Early winter (late winter okay but excessive running sap may weaken the tree). Good for major clean-out and thinning. No bugs to fight or bulbs to trample. Summer (after leaves are full size). Good to see foliage masses for thinning and layering. Easier to identify dead branches. Anytime of year to remove dead or problem branches.

3 BASIC STEPS

1. Clean Out: Remove branches which are dead, broken, crossing (within reason — some may be unavoidable).
2. Thin: Open up light and air circulation. Balance the branch density around the tree.
3. Layer: Create “clouds” & spaces between them (but don’t over-thin inside). Preserve foliage masses at ends of major branches. Open up views of attractive/unique branching inside.

HOW MUCH TO REMOVE?

Try to not remove more than 1/4 of the volume of the living crown (some say no more than 1/8) in one year. More may cause oversprouting. Anything dead, of course, should be removed.

TOOLS

“Fruit” or “floral” pruner (narrow blades), hand pruner, lopper, folding hand saw. For larger trees: large hand saws, pole pruner.
Other equipment: safety glasses, gloves, ladders. LOOK before moving around — save your eyes, body and the tree!

MISCELLANEOUS WISDOM

Work from inside out, bottom to top, small branches before larger. Work around the plant at least twice (if possible). You will notice different details each time. Always do less then you think you need to. Revealing natural beauty takes patience.


PRUNING TIPS... Redirecting branch growth:

Creating layers:

Removing large branches: