purple / black spots

jonathandbApril 10, 2007

I wonder if any one has an idea what is going on with this otherwisw healthy rhododendron? The under side of some of the leaves have light purple blotches, on the upper leaf surface corresponding to the purple blotches are dark purple/black blotches with some brown.

Any ideas thanks.

Thank you for reporting this comment. Undo
morz8(Washington Coast Z8b)

There are about 10 different fungi that can cause leaf spot on rhododendron...and while I haven't seen it here near the coast, powdery mildew is becoming more common on our rhododendrons.

Leaves infected with powdery mildew may become off color and exhibit the white powdery fungus growth associated with the disease, or some rhododendrons lack the white powder and instead show yellow or purplish spots on the upper leaf surface and discolored areas on the lower leaf surface.

My advice without a picture to show us would be to take example leaves exhibiting the symptoms to staff at a reputable nursery (not a box store) or county extension agent for an accurate diagnosis. Funginex sprayed at the appropriate time can be helpful and I've heard Bayleton recommended too since it's systemic and can be easier to apply to large shrubs - but it's expensive so best to know for sure what you are treating.

    Bookmark   April 11, 2007 at 9:01PM
Sign Up to comment
More Discussions
How do I get rid of this growth on my azaleas?
How do I get rid of this growth on my azaleas? They...
Most mini
I bought one purple blooming azalea years ago in Laconia...
help! trying to identify the issue...
I live in Tulsa Oklahoma (zone 7) and purchased these...
Good site to order blue?
Hi, I am looking for a west coast nursery that sells...
Tiny white specks on Rhododendron?
I have a 6 year old rhododendron (Virginia Richards)...
Sponsored Products
Belham Living Hampton Chair Side Table - Black - KG-045-BK
$129.99 | Hayneedle
Cico Egg Cup by Alessi
$22.00 | Lumens
4 Watt MR16 LED bulb
Super Bright LEDs
Black & Decker 6-cup Rice Cooker
A19 Lighting | Antigua Pendant Light
$137.99 | YLighting
Rotaliana | Luxy W1 Wall Light
$549.00 | YLighting
Runner: Taranto Black 2' 6" x 8'
Home Depot
1960 Skee Ball Blueprint Wall Art
$129.99 | Dot & Bo
© 2015 Houzz Inc. Houzz® The new way to design your home™