Q.sad looking Rhododendron
My large Rhododendron is looking very sad and was last year, though it flowered a lot. This year, the leaves look as though they are very sad. Can you tell my why? We live in East Anglia, have acidic soil and a profusion of Rhody’s. The smaller plants seem to be fine but the larger one over 6 ft looks very sad. They are all in the same location in the garden. It is a large Bright Red. We have only been here 1 year and it looked a bit sad then (March) like a dog with its ears down. It’s been fed with Iron and a specific Rhody feed.
It's safe to say your older Rhododendron is compromised in some way. Inspect it carefully for any infestations, leaf or stem damage.
Since the plant is much larger then the others in your yard, has the plant been pruned properly? If the plant has been struggling for the last year, perhaps it suffered some type of stress or disease prior to you owning them.
Please read though these links.
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/pruning-rhododendrons.htm