Silver Maple Blight


Possibly you can diagnose and treat phytopathology or parasitism in trees. If so, do you have any ideas on this black, black ooze that’s emanating from the bark of our giant silver maple?


There are a number of different types of canker and similar diseases of tree bark. Bark diseases progress at various rates, but they usually take a season or more.

For details on canker diseases, see the Morton Arboretum fact sheet here. And specifically, on the phytophthora bleeding canker to which silver maples are susceptible, and which may be the culprit in your case, there is a University of Massachusetts fact sheet here.  For information on wetwood or slime flux, which your photo also suggests, you can refer to another Morton Arboretum fact sheet here,

Some trees can live a long life after having been infected; however, this may create a structurally dangerous tree or limbs. Given that this is a “giant” tree and may pose a risk to your house / property, we recommend you contact a qualified arborist in your area, as soon as possible, to make a diagnosis and recommend actions.

To locate a certified arborist in your area, you can use the professional association’s tool here.

Best of luck with your tree.