Hello Silversurfer,
Thank you for your reply.
Yes indeed the plant in question is over twenty years old and during the last few years I've known it it has never gained any height filling out lower down instead. I'd say the current height is between 3-4 ft.
It seems to like the slow release organic fertiliser I give it every springtime.
Rhododendron impeditum......yes it could well be that.
What I need to do is explore how to propagate because a quick look round the internet at nurseries with Rhododendron impeditum show quite a lot of apparent variation.
The flower colour on the plant in question is quite intense not shown here by the photos.
Have you ever tried to propagate yours?.
