Marianne's Response
Infected Japanese maple tree
Hi Marianne, we have a huge red Japanese maple tree about 20 years old and 35 feet tall. We noticed that there is some sort of sap on some branches (actually we saw dark holes on the ground it made) and the bark is gone. I am sending a picture along. What could it be? I seem to notice it before the dry weather; other than some branches being very dry, the tree seems healthy
Posted by Rubysliperss on July 22, 2015
Marianne's Response
The photo you send indicates your maple may be suffering from Canker (not the same as cancer) and it is caused by a fungus from Phytophthora. Healthy trees will outgrow it but you should remove the infected area being sure to dip your pruning shears into bleach when pruning. Look for any cracks at the base of the tree and paint these with a pruning paint to keep new fungal spores from entering the tree sap.
Keep growing,
Marianne Binetti
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