When Should We Trim Our Japanese Maple?

Question:

We have a 30 year old beautiful Japanese Red Maple tree in our front yard that is getting way too tall and wide. It is getting near wires and hitting the house. When is the best time to cut it back and give it a good trim and shaping?

Hardiness Zone: 7a

Jan from Long Island, NY

Answer:

There are many conflicting opinions regarding when to prune maples, so mine may be just one more! All species of maple are known to be bleeders (seep a lot of sap after pruning).

To minimize the amount of seeping, major pruning should be done during the dormant season (after the leaves have fallen). For most gardeners, this will be either in the late autumn after the sap has fallen (November) or early spring before it starts to rise (February/March). Personally, I think late autumn is best. Fallen leaves (and temperatures) are an easy signal.

The rising of spring sap seems harder to predict. Pruning your tree during this time may still cause some seeping, but there is less sap movement during these times so it should be minimal. There is also less threat of insects and disease.

Above all, make sure to make clean cuts using sharp, sterilized tools. Wounds with clean cuts will form a callus and seal over much more readily than those with jagged wounds.

In most cases, it's best not to seal up seeping wounds with tree-wound paint. Most tree experts agree that if any disease spores are present, covering them with wound-paint simply seals them in from the elements and provides them with a safe environment where they can really go to town. Healthy trees are better left to heal on their own.

Good luck!
Ellen