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fungus like growth on my rhodies which prevents flowering/ How to combat this #866858

Asked May 03, 2024, 9:15 AM EDT

Please see fillable pdf attached

Windham County Vermont

Expert Response

Hello John,

I’m sorry to hear this! Do you happen to have photos you can provide for more accurate assessment of the issue? 

Thank you!

An Ask Extension Expert Replied May 06, 2024, 10:11 PM EDT

Hi John, 

Rhododendrons require specific environmental conditions, just like most plants. In the Rhodo's case - moist but well drained acidic soil (4.5-6.0), ample space to grow, and proper aeration. Of course, in spite of these things, there are a number of diseases/pests/ injuries that can cause them damage!

In the absence of photos or more information, I couldn't diagnose your issue, but I did do some research for you to look over on possible causes, and preventative/proper care for Rhododendrons that may help you: 

- This provides a basic overview of insect/pathogen/fungus/injury causes for Rhododendron issues which can be helpful in determining what you might be dealing with - and also provides some great basic care information: 

Azaleas and Rhododendrons: Identify and Manage Problems | University of Maryland Extension (umd.edu)


- This resource gets very technical, but has a detailed breakdown of many common pests and diseases. I see a few that seem to fall in line with the symptoms you provide - check out exobasidium leaf gall, Azalea Bark Scale, or Aphid damage to start. I was most struck by the description for these as they included fungus/mold like growths, yellowing leaves, and possible loss of new flowers. 

eb1229.pdf (se-ars.org)


- This resource provides some generals on Rhododendron and Azalea care and has links to a number of contributing articles for further research

Rhododendron and Azalea Insect and Disease Management


Hope this helps as a start, and feel free to reach out with photos if you need further help diagnosing! 


Best, 
Kristin


An Ask Extension Expert Replied May 08, 2024, 1:44 PM EDT

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