Quaking aspen tree with black spots on leaves

Asked May 11, 2016, 11:45 AM EDT

We love quaking aspens and wanted to add one to our yard. Two summers ago we planted one and it seemed to be doing well, but then developed black spots on all of its leaves. We did some online research and tried to treat it by removing all leaves except the (very few) healthy ones. It did grow new leaves and seemed to be "cured". It over-wintered fine, but then when leaves emerged in the spring they quickly developed the black spots again. We decided to try with a whole new tree, thinking perhaps that one was compromised and susceptible to the black spots for some reason. We planted a perfectly healthy quaking aspen that we bought at a gardening center; now it has developed the black spots too. Are aspens just especially susceptible to this? Is there a way to treat it so that it will stay away? The tree gets ample sunlight and is not crowded or even near other trees. Thanks for any ideas you might provide, Christine Tamez

Hennepin County Minnesota

1 Response

There could be a number of diseases and infections that can cause this problem. Without some good quality photos I'd only be guessing, however.

Here is a link that has pictures and descriptions of the most common Poplar problems. The links also include treatment options:
http://www.extension.umn.edu/garden/diagnose/plant/deciduous/poplar/leavesspots.html

I hope this is helpful. Please contact AaE again if you have further questions.