Here in Raleigh, NC, Rhododendrons die from Phytophthora root rot. Many live up to 8 years with some disfiguration, but in a recent study, ARS reports that R. x 'Caroline' Gable is totally immune to the disease. They think this is because it has a very different root structure than olher Rhododendrons. Has anyone experimented with grafting other varieties onto 'Caroline' rootstocks? Perhaps this would provide plants that are immune but offer a wide variety of flowers and habits. Breeding with 'Caroline' is another approach, but I won't live that long. So, if I could find an inexpensive source for 'Caroline' rooted cuttings (where I don't have to buy hundreds), I'd like to try grafting, assuming it hasn't been tried already and failed.