Orange spots hurting trees

Asked June 25, 2017, 10:09 AM EDT

The picture was taken 5/26/2017 in my back yard. I was not able to identify the tree. The neighbors have several large versions of the tree. In recent weeks much of the effected trees have turned brown on approximately 5-10% of the large trees and 50% or more of small trees. I also have some small eastern red cedars (I think) I have more pictures but 5mb limit. I have noticed the grass around the small cedar(?) has orange spots on it, I think it may be the same thing?

Cecil County Maryland grass ash trees trees

1 Response

Based on your photos this looks like it may be an ash tree affected by a rust disease. This disease will not kill the ash and we do not recommend treatment.
However, ash trees are susceptible to the emerald ash borer, an invasive pest.
Begin by looking at the emerald ash borer information on our website. There are photos of ash tree identification. http://extension.umd.edu/hgic/invasives/emerald-ash-borer

If the trees are in good health, consider protection. Consult the North Central IPM Center's fact sheet Insecticide Options for Protecting Ash Trees From Emerald Ash Borer as well as a decision guide by Purdue. Large specimen trees will need to be treated by a certified arborist. http://www.treesaregood.org/

There are homeowners options for treatment but the trees have to be within a certain size ( this is DBH - Diameter at Breast Height).
At this point, you should contact several certified arborists for an onsite diagnosis regarding the health of the trees and the best way to proceed.

Lawn - rust diseases may infect most of the turfgrasses grown in Maryland. The grass usually grows out of it and does not kill it. Keeping the turf mowed usually controls it. See our website for more information
http://extension.umd.edu/hgic/rust-lawns

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