Sick aspen

Asked June 18, 2018, 2:52 PM EDT


I'm seeking help for a sick aspen tree on my property. When I bought my house 12 years ago, I had a total of 5 aspen trees in my back yard. Three of them have died, so we took them out.

I have two that are approx 30 feet tall and the trunk is approx 7" in diameter.

One is really green and healthy, and the other has smaller yellow leaves (all season), and for as long as I can remember. I'm not sure if they are the same variety or the one has been sick for a long time. The leaves are much larger on the healthy green aspen tree. I will attach a picture of the healthy green leaves on one aspen vs the small yellow leaves on the sick tree. They are planted approx 4 feet apart.

I will also attach a pic of the yellow leaves with brown tips and now spots.

In the past week, all the leaves are developing spots all over.

I planted a young aspen a couple years ago, to replace my last one that died. Will it get sick too?

How and when can I treat this tree? If its possible to save the tree.. I've read about iron deficiencies and several fungus diseases. I'm confused and don't know where to start.

I appreciate any help you can offer to save my tree.

Thank you,


Yellowstone County Montana

1 Response

Nothing is more classic to the Rocky Mountain West than aspen trees, but alas, in the landscape they often do not fair well. They typically only have a life expectancy of about 25 years in the home landscape. They are often harvested from the wild with only a limited root system. Also, out of the mountains, they are subject to a lot of stress. Water, heat, insects and diseases all impact aspens. You leaf spots look suspiciously like septoria leaf spot, but only a lab can tell. I am attaching a link to our aspen page which will give you some guidance. The links are for Colorado, but the information will work for the Billings, MT area as well.