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Thursday - May 29, 2008

From: Kyle, TX
Region: Southwest
Topic: Trees
Title: Bark problems on Platanus occidentalis (American Sycamore)
Answered by: Barbara Medford

QUESTION:

I got home today, after two hot sunny days, and found that one of the sycamores (street tree) planted last year (3-4" caliper) has vertically split and peeling bark on the south side of the trunk (large chunks are sheeting off - maybe this is normal for Sycamores). Another one has what looks like sunburn all along the south side of the trunk up to about 7 or 8 feet high; the bark on this one is darkened and dull where it is sunburned and the bark is beginning to split too and it looks like there might be some small insect beginning to chew in the exposed trunk.

ANSWER:

First, the good news. It's perfectly normal for bark to peel off a Platanus occidentalis (American sycamore).

On the other hand, this tree has several liabilities. Some of those that might apply in this case are:

Anthracnose: This Colorado State University Extension website has a good description of this fungal disease; however, it appears symptoms are more likely to appear in leaves than bark.

Canker stain: First, see this Texas A&M website on Trees, scroll down to "Sycamore," reading especially the paragraphs on anthracnose and cankers. This Pennsylvania State University College of Agricultural Sciences site has more diagnostic information. Finally, take a look at these pictures of canker stain, and compare them with the symptoms on your trees.

American plum borers: A description of this pest of fruit and ornamental trees is found in this Cornell University Integrated Pest Management site on the American Plum Borer. And, again, pictures of the beastie.

Sycamore lacewings: This Ohio State University Extension website on Lace Bugs details their appearance and treatment, but says they are seldom a serious threat. Again, the symptoms of this would show up more in the leaves than the bark of the sycamore.