japanese maple problem!!

Asked September 23, 2018, 12:21 PM EDT

HI, In July, I had a weeping Japanese Maple pruned, Recently noticed new growth doing well, but older leaves and bark showing severe problems. Specifically, leaves discolored (losing color, maybe a mildew?) and then drying up. Also, the bark has large areas of discolor. I attached pictures. Note, there is some healthy new growth right next to sick branches and leaves. Please help. I love this tree. (A lot of weeds have grown underneath the tree since it was pruned and light has gotten through. But I doubt that's the problem - right?). Thanks!! I have more pictures available if that'll help,

Montgomery County Maryland

1 Response

The Japanese maple overall does not look that bad.
We notice lichens on the trunk in the left photo. This is not a reason for decline. They grow on mature trees and are a sign of good air quality. http://extension.umd.edu/hgic/topics/lichens

Middle photo - We notice some leaf scorch and anthracnose , a fungal disease on the foliage. This time of year the tree can look pretty beat up due to environmental stresses, poor site conditions, and maintenance. There should be enough reserves in the root system to put out new growth next spring. No control is necessary.

Right photo - the tree has put out new growth and this is a good sign. However, this growth may be damaged by cold temperatures but there is not much you can
do about it. In general, Japanse maples grow best in morning sun and afternoon shade. Keep them watered during dry periods and make sure mulch is no thicker than several inches and away from the base of the trunk. Prune dead wood.
Take a look at our blog post on Japanese maples https://marylandgrows.umd.edu/2018/08/24/japanese-maples-in-maryland-landscapes-plant-location-care-...