Evergreens dying

Asked May 5, 2020, 12:18 PM EDT

We have many mature blue & green spruce evergreens on the property. We moved here 4 years ago. Every year from the bottom branches are dying. I believe they have a Blight. I’ve removed many bottom branches and would like to save the trees! Is there a fungicide that is recommended for this disease?

Livingston County Michigan

1 Response

Hello!

Thank you for using the Ask an Expert Service. Before treating large landscape trees with fungicides, I would suggest consulting with an ISA-certified arborist, if possible. (ISA = International Society of Arboriculture) There are multiple issues that can cause needle drop on spruce. You can search for an ISA-certified arborist near you at https://www.treesaregood.org/findanarborist/arboristsearch .

You can also consult with the MSU Plant and Pest Diagnostic Services (pestid.msu.edu). Note modified operations. I think it would be best to send them some photos first and discuss the issue, before potentially sending in samples. I would suggest taking some more photos, including some that capture even more of the whole trees. Also, take some pictures of branches with needles, and close-ups of the conifer needles.

I would suggest checking out the article What is spruce decline and what should you do about it? from MSU Extension.

IF the main issue is Rhizosphaera needle cast (which, as I said, should be verified), you can use a protectant fungicide, such as one with the active ingredient chlorothalonil, to slow the spread of the disease to the new needle growth. It will not cure tissue that is already dead or infected though. And you must get good coverage of the product on the tree and might want to do 2 applications annually (one in spring, so pretty soon, and one 3 or 4 weeks later). Always read and follow all pesticide label instructions. You might want to get a professional to treat large, mature trees.

Here are a few articles on Rhizosphaera needle cast:

Rhizosphaera needle cast from U. of Minnesota Extension

Rhizosphaera Needle Cast from PennState Extension

Rhizosphaera Needle Cast from U. of Wisconsin Extension

By the way, it looked like in a couple of the close-up photos you were focusing on the lichens. Lichens are not the issue. They are a harmless growth complex on the surface of the tree. But, if you were concerned about them, you certainly would not be the first. Here is an article:

https://www.canr.msu.edu/news/lichens_a_partnership_in_nature_that_survives_in_diverse_environments

Please let me know if you have further questions!

Best,

Irene