Brown spots on Japanese Maples
Sheila Asked
What the brown spots are on my Japanese maples?
The Gardener’s Answer
Hi, Sheila: Japanese Maples (Acer palmatum) are susceptible to a variety of insect and disease issues. From the picture that you sent, it appears that your tree may have a fungal disease and cankers have developed. Take a sample to the horticulture agent at your County Cooperative Extension Service for diagnosis. They will be able to give you a definitive answer or send the sample off for analysis. Use a sharp pair of pruners and remove the infected branch back to the nearest intersecting branch. Be sure to dip your pruners in alcohol before making another cut. This will help to prevent disease spread. Plants that are not grown in ideal conditions can become stressed and more susceptible to insects and disease.
