For the first time in approximately 10 years my Rhododendron which is gwoing in a large pot seem to have developed brown spots on most of the leaves which looks unsightly, what is this disease and how should it be treated?
could be a fungus ... can you post pictures, please?!
Is this something that can be treated with a Spray and also once treated will the disease be brought under control and not affect new leaf growth?
Hi, hard to say without a picture, but there is Rhododendron leaf spot. Spots are brownish/purple with clearly defined edge and this is caused by fungus which can be treated with a fungicide. But also need to take steps to improve plant vigour, new compost would help or fresh top dressing if it has had new compost fairly recently and regular feeding and water at base.