What is wrong with this plant?

[420benz]

This is pmj Rhododendron.

 

[Becky]

I'm not certain, but it looks like it might be lacebug damage

 

[420benz]

Anyone know for sure ?

 

[Chuck]

I am pretty sure it is either powdery mildew or downy mildew, two separate and different things

 

[420benz]

How to treat both?

 

[Chuck]

How to treat both?

On powdery mildew a good organic method is to spray with baking soda or if you can get whole milk spray with that. If not that spray with a copper based fungicide. On downy mildew there is no cure only preventative measures. Do not water overhead, add air circulation, keep the ground under the plant clean.

Powdery mildew looks a little different. It actually looks like a grayish white powder has been dusted over the plant. Downy mildew looks sort of like a spider web. An almost microscopic whiteish threadlike substance.

 

[420benz]

Thanks for all of the help.