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Blue spruce fungicide #828203

Asked May 02, 2023, 7:31 PM EDT

What is the best fungicide to spray blue spruce trees. I read your article relating to this but did not see best spray. Thank you

Shiawassee County Michigan

Expert Response

I would be happy to help but need a little more information. Are these trees currently displaying symptoms, or are you looking for something prophylactic?

Thank you for contacting Ask Extension! Replied May 02, 2023, 9:49 PM EDT
Good afternoon,

I have around 30 trees at one location on a burm for privacy landscaping these are 15 years old. Some of these are definitely showing signs that i do not believe were bad last year. Some are in good shape yet. I also have some blue spruce about 6 ft tall that I just planted that are in good shape yet that I want to be proactive with. Attached photos are same trees, road side is damaged looking and property side are in great shape. I was told dithane 45 is what I should get but want to be sure first. Thank you for your time. 

Brent


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On Tue, May 2, 2023 at 9:49 PM, Ask Extension
The Question Asker Replied May 03, 2023, 6:01 PM EDT

For some reason only the first photo showed up, and the trees look pretty good. Can you upload the other image again? Are you sure it's needlecast and not road salt damage?

Thank you for contacting Ask Extension! Replied May 03, 2023, 6:38 PM EDT
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Here are photos showing damage to branches. Road salt could be a possibility, however the berm is like 25 ft from road and thos is first year I have noticed damage so I am not sure. Thank you 

Brent



On Wed, May 3, 2023 at 6:38 PM, Ask Extension
The Question Asker Replied May 03, 2023, 7:15 PM EDT

Yes, that is most likely needlecast. You want a fungicide with active ingredient chlorothalonil, copper hydroxide or mancozeb. Dithane 45 is mancozeb, but it comes in different formulations. If you use that (or any fungicide), make sure you get the formulation with needlecast in conifers on the label and use according to label directions. It should be applied when the new needles have reached half their projected final length, with a follow-up application as soon as needles are fully elongated. Let me know if you have questions. 

If you haven't read these articles, you may find them helpful:

What is spruce decline? and Help me save my blue spruce.




Thank you for contacting Ask Extension! Replied May 03, 2023, 9:23 PM EDT
OK thank you for the help. You know the best place to purchase this I've looked at my local farm stores and they don't have anything? 


On Wed, May 3, 2023 at 9:23 PM, Ask Extension
The Question Asker Replied May 08, 2023, 12:47 PM EDT

There are plenty of online sources. One example is https://www.forestrydistributing.com/mancozeb-fungicides

You will need to check the label to make sure it is properly labeled, and follow all safety and application information, or hire a certified arborist to apply.

Thank you for contacting Ask Extension! Replied May 12, 2023, 11:44 AM EDT
Ok. Thank you for all your help! Have a great weekend.

Brent


On Fri, May 12, 2023 at 11:44 AM, Ask Extension
The Question Asker Replied May 12, 2023, 12:08 PM EDT

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