Black/brown spots on tree leaves - Ask Extension
Starting this year, I have noticed that these black spots started turning up on some of the leaves and it seems to be spreading. What is this? Is it ...
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Black/brown spots on tree leaves #876933
Asked July 12, 2024, 8:58 AM EDT
Starting this year, I have noticed that these black spots started turning up on some of the leaves and it seems to be spreading. What is this? Is it dangerous for the tree? How do I get rid of it? Also, if you happened to know, what kind of tree is this? Is seems to be pretty slow growing (14 years to grow around 10 feet).
Thank you for any help you can provide!
Larimer County Colorado
Expert Response
Hi Bill,
This looks like it could be hedge maple (Acer campestre) - it's definitely one of the smaller ornamental maples. There are several, including ginnala, boxelder, etc. These do grow more slowly, since their mature size is going to be less than 30 feet tall.
As for the spot on the leaves, we've seen a number of diseases on trees and shrubs this year - both fungal and bacterial. These occur in early spring when things were more wet - and can infect the leaves when it's still in bud. At this point, there is nothing you can do, since infection has occurred. It's unlikely to spread to other parts of the tree this season.
The leaves may shed early, and when they do, rake them up and throw them in the trash. This can help break the disease infection cycle in the spring.
This looks like it could be hedge maple (Acer campestre) - it's definitely one of the smaller ornamental maples. There are several, including ginnala, boxelder, etc. These do grow more slowly, since their mature size is going to be less than 30 feet tall.
As for the spot on the leaves, we've seen a number of diseases on trees and shrubs this year - both fungal and bacterial. These occur in early spring when things were more wet - and can infect the leaves when it's still in bud. At this point, there is nothing you can do, since infection has occurred. It's unlikely to spread to other parts of the tree this season.
The leaves may shed early, and when they do, rake them up and throw them in the trash. This can help break the disease infection cycle in the spring.
