View Full Version : Is this powdery Mildew?

02-22-2011, 11:20 PM
I'm wondering if this is normal for Rhododendrons? These are Rosebays, native to Asheville NC where I'm from. I installed them a year ago. What do you guys think, should we be concerned?


Think Green
02-22-2011, 11:38 PM

This is what you think it is.
I see a normal Rhododenderon on your photo.........just the same as our Azaleas.

Think Green
02-22-2011, 11:40 PM
Watch it closely for bud blight or bud blast.

02-23-2011, 12:13 AM
So?...They normal have that fuzzy junk on them? I thought it was a possibility but it does seem excessive. They look healthy otherwise.

Think Green
02-24-2011, 06:37 PM
The only thing the pic resembles is possible scale.
The other thing I can see is curling of the leaves and yellowing buds. Have you had drought??
Turn over a leaf and see if there are piercings that is causing these whitish indentions in the upper leaf surface. This could be mites.
You can do the white paper test to see what if any insects fall off the leaves. Place a white piece of paper under the plant and shake the plant softly. Stuff will fall off!! Go from there as far as leaf insects.
The pic doesn't look like mildew to mel!!!That is what I am trying to advise. Those leaves should be waxy and completely green in color without any stippling at all. Sorry for not further posting earlier.
Azaleas and Rhodies do and can have this fuzz on the leaf and stem however, the curling of those leaves and yellowing cautions me. Have you taken a stem and leaf sample to a local nursery or extension service?? This is the first thing to do before anything gets out of hand.

02-25-2011, 10:17 AM
Thanks thinkgreen, I will take a cutting to a nursery next time I go. Here are some more pics.

Thank you

02-28-2011, 04:14 PM
Rhodo's love acidic soil. Get some Miracid from the local garden store, read the directions and hit it a couple times a year. That should help with the yellowing..

02-28-2011, 04:44 PM
They will appreciate it at the nursery if your sample comes in in a bag, so any potential pest or pathogen is not spread to their stock by accident. I mean no offense in saying that if you already knew it.