Coral bark maple turning black and Gray - Ask Extension
I’ve been searching the Internet extensively for about the last two weeks when my coral bark maple suddenly turned black and the leaves started turn...
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Coral bark maple turning black and Gray #767505
Asked August 16, 2021, 1:48 AM EDT
I’ve been searching the Internet extensively for about the last two weeks when my coral bark maple suddenly turned black and the leaves started turning yellow and red autumn colors.
My church friend who is also a master gardener appears to have no advice for me so I thought I would seek a second opinion.
Attached are pictures of the tree. It’s a winter flame Japanese maple.
I have no idea what the problem could be as there are so many possibilities. from over and under watering, too much sun exposure, bacterial leaf scorch and even for Verticillium wilt I’m absolutely overwhelmed.
I’ve also been told it looks like tight bark disease. This current condition was brought on over the last few months after the hot and dry weather. The trees truck bark just turned brownish black and the leaves started to wither and die.
If you could take a look and give me a better idea I would be very grateful. I’m also interested in potentially joining a master gardeners association close to me where I can continue my education and try and keep my yard alive!
Thanks in advance for any help and advice you can offer!
Washington County Oregon
Expert Response
Your coral bark tree was sunburned during the recent heat waves.
Coral bark maples have thin bark and, thus, are easily sunburned. To prevent further damage, do the following:
1. Rig temporary shade from the sunny side such that a shadow is cast onto the trunks and branches. To do so, drive several tall stakes into the ground at least 2 feet away from the trunk, then attach shade cloth or old sheet to the posts. You can obtain shade cloth from most garden centers and big box stores.
2. Consider painting the affected woody portions with matte white paint.
3.a. The brown leaf tips and autumn-colored leaves reveal a serious water shortage. If you planted the tree this year, the rootball may need to be watered every 1 to 2 days during heat spells.
3.b. Also, water to the dripline -- the large imaginary circle on the ground, directly under the branch tips -- once a week until the fall rains begin. (See page 11 of "A New Tree" - click here.)
Coral bark maples have thin bark and, thus, are easily sunburned. To prevent further damage, do the following:
1. Rig temporary shade from the sunny side such that a shadow is cast onto the trunks and branches. To do so, drive several tall stakes into the ground at least 2 feet away from the trunk, then attach shade cloth or old sheet to the posts. You can obtain shade cloth from most garden centers and big box stores.
2. Consider painting the affected woody portions with matte white paint.
3.a. The brown leaf tips and autumn-colored leaves reveal a serious water shortage. If you planted the tree this year, the rootball may need to be watered every 1 to 2 days during heat spells.
3.b. Also, water to the dripline -- the large imaginary circle on the ground, directly under the branch tips -- once a week until the fall rains begin. (See page 11 of "A New Tree" - click here.)
A recently-planted tree requires supplemental water for 2 years, which is then gradually decreased to its normal requirement. After 2 years, water every 2 to 3 weeks to the dripline during our dry months, depending upon the prevailing temperature.
The trunk appears severely damaged. A general guide is that if 50 percent of the circumference is healthy, the tree will survive. The other question, though, is whether it will be stunted. So, depending upon how well the tree recovers by next year, consider replacing it in the fall of 2022.
