Q.Why Is My Rhododendron Orange?
Hi, I have three rhododendron plants in soil in front of hedges in my house garden in the North East of England. They have never had any issues previously and I think they have been there for about ten years. They flowered this year, no issues. I have just noticed 10-20% of the leaves on the lower canopy are now bright orange/yellow and falling off, there are also holes in the leaves. The branches stems appear yellow/orange too. The one that seems most affected is near a dead tree but the other ones are further away from the tree. I have tried to look at what diseases may be affecting it, but nothing seems to match the exact symptoms. Please help!
Certified GKH Gardening Expert
This looks a lot like Phylosticta or Cercospora infections. Either way, treatment will consist of fungicides and meticulous cleanup. This will definitely start to spread to nearby plants and trees. It might be what killed off the nearby tree.
Treating with fungicides and keeping every bit of infected growth cut and away from the area will be your best options.
https://www.gardeningknowhow.com/plant-problems/disease/cercospora-leaf-spot.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm
