A few weeks ago, I asked for people to send me some questions on plants. I received one question about tree dieback, specifically about the Sycamore tree. I have finally got around to a bit of time to look up this issue.
First of all, let me tell you about something that I learned last year at one of our Master Gardener classes on hardwood trees. The expert spoke about what happens to trees in times of drought, I specifically remember something he said about oak tree species. When they are stressed, they begin to shut down support to the very tips of the branches. This causes, in the middle of summer, quite a bit of brown tips of branches, about 12" or so, to fall off and scatter all over your yard.
So, while you may think something is "wrong" with your oak trees when you see this, your tree is really attempting to save itself from total dessication. So, don't worry.
As far as Sycamore (Platanus species)trees go, there are a number of issues that hit these trees, but they are very strong. The big one is Anthracnose. I found this very succinct information on the South Carolina Extension Office website:
Anthracnose (Leaf & Twig Blight): Anthracnose is the most serious disease of American sycamore, but generally causes only minor damage to the London plane tree. It is caused by the fungus Apiognomonia venata (asexual stage - Discula platani). This disease may appear as four distinct phases:
Twig Blight: This phase occurs in the spring before leaf emergence, killing tips of small, 1-year-old twigs.
Bud Blight: This phase occurs in April and May. The expanding buds die because of the girdling action of the canker on the branch.
Shoot Blight: New shoots and immature leaves on infected branches suddenly die.
Leaf Blight: The most characteristic symptoms are crinkling and browning of the leaves. Entire leaves may be killed and then fall. These symptoms are very similar to those caused by late spring frost injury.
So, while it may appear to be an issue, most of the Sycamore trees can be affected by Anthracnose, but it does not usually cause death of this tree species. I just have to tell you that I was recently reading a book (the name escapes me right now) in which they described Sycamore trees as "the ghosts of the forest". I just love that phrase and think it every time I see one now! I know, I am a bit of a tree geek, but I think that this is just beautiful!!
See you at the Master Gardener table at the 4-H Fair, Frying Pan Park on August 5!!
Molly
Paul J Noel
12:22 pm on Tuesday, January 8, 2013
There was an enormous stand of Sycamores in Cambridge MA near Harvard University on Soldier's Field Road that have dwindled to half what was there before. How can you then say this is a strong tree that won't die from these blights ? They use to cover the entire road like a magnificent canopy and they are either gone or on their way out on both sides. The are replacing them with small ones that look as unhealthy as any tree I have ever seen .This is far worse than you mention here. The proof is simply there. These magnificent trees have simply died.
Molly O'Boyle
9:00 pm on Tuesday, January 8, 2013
Paul, thank you for your comments. Since I have not been to Cambridge, MA, I don't know what other conditions may be present for the trees you mention. They may have been stressed by root issues or chemical issues from treating roads in the winter. When plants get stressed by one factor, another might attack like the anthacnose. So, while the plant might have died from the anthracnose, it could possibly not been the immediate cause of stress on the plants. I appreciate your thoughtfulness. Thank you.