Silver Maple - Bleeding Canker? - Ask Extension
I have a large 3 ft diameter silver maple that has developed what looks like a bleeding canker on its trunk. Earlier this year I noticed some fairly ...
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Silver Maple - Bleeding Canker? #406833
Asked June 13, 2017, 4:14 PM EDT
I have a large 3 ft diameter silver maple that has developed what looks like a bleeding canker on its trunk. Earlier this year I noticed some fairly large dead limbs & recently noticed a wound of some sort on its trunk that appears to be seeping liquid. Can you tell what it is from the attached photos? Is there something I can do to prevent the tree from dying? What can I do?
Hennepin County Minnesota
Expert Response
Thank you for the question. There are a number of different types of canker and similar diseases of tree bark. Diagnosis should be done by a certified arborist, and probably sooner than later because of the size of the tree, it's obvious value in your landscape, and its proximity to your house.
Bark diseases progress at various rates, but they usually take a season or more. Some trees can live a long life after having been infected with certain diseases; however, this may create a structurally dangerous tree or limbs. The canker may be the cause for the branch dieback seen.
Removal of tree or limbs may be needed for safety reasons, but removing the bark tissue around the infection site(s) is not recommended. Fungal treatments are not generally effective, and opening the wound can actually exacerbate the disease.
Bark diseases progress at various rates, but they usually take a season or more. Some trees can live a long life after having been infected with certain diseases; however, this may create a structurally dangerous tree or limbs. The canker may be the cause for the branch dieback seen.
Removal of tree or limbs may be needed for safety reasons, but removing the bark tissue around the infection site(s) is not recommended. Fungal treatments are not generally effective, and opening the wound can actually exacerbate the disease.
Read here about phytophthora canker, a canker disease that silver maples are susceptible to:
Read here to learn how to hire a professional arborist: https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/how-to-hire-a-professional-arborist/
Thank you for contacting Extension.