Quaking Aspen black spots on leaves - Ask Extension
Our 3 year old otherwise healthy Aspen has black spots and curling leaves. It was also very late setting on leaves this year. I thought the buds had ...
Knowledgebase
Quaking Aspen black spots on leaves #191105
Asked June 14, 2014, 10:23 AM EDT
Our 3 year old otherwise healthy Aspen has black spots and curling leaves. It was also very late setting on leaves this year. I thought the buds had gotten nipped with a late frost but maybe the 2 problems are connected? Yikes! I don't want to lose this tree . :(
Cass County North Dakota
Expert Response
Good morning,
It's hard to tell for sure from the photo, but it may be a fungal disease called Septoria leaf spot (and canker). The fungus enters the leaves in the spring and kills some of the leaf surface, causing black spots to appear.
Treatments are for prevention only, not curing the disease. Fungicides labeled for treating Septoria include some with the active ingredient chlorothalonil, or those with mancozeb. Treatments should be applied before wet-weather conditions that would favor infection. Always follow label instructions when using a pesticide.
In the fall, be sure to rake up and destroy all the leaves that drop, as the fungus will over-winter in fallen leaves.
Best wishes,
It's hard to tell for sure from the photo, but it may be a fungal disease called Septoria leaf spot (and canker). The fungus enters the leaves in the spring and kills some of the leaf surface, causing black spots to appear.
Treatments are for prevention only, not curing the disease. Fungicides labeled for treating Septoria include some with the active ingredient chlorothalonil, or those with mancozeb. Treatments should be applied before wet-weather conditions that would favor infection. Always follow label instructions when using a pesticide.
In the fall, be sure to rake up and destroy all the leaves that drop, as the fungus will over-winter in fallen leaves.
Best wishes,
