If you look at their web site - although they do have a rhododendron pictures banner that runs near the top - already they are not one of the plant types that they direct attention to on the welcome page.

Maybe it has something to do with foliage mildew or lace bugs, the expense and bother of getting each crop past these. I do know that Exbury is supposed to have given up on spraying for mildew after it had gotten to the point where they were spending 50,000 pounds per year on it (to keep susceptible kinds clean you have to spray over and over each growing season, like with fungus susceptible rose varieties).

Otherwise when I was on a field trip to Briggs many years ago the head of the lab came outside and talked to us, said we weren't going to get a tour because they had been fighting thrips for some time and didn't want any possible bringing into the lab of more of them by one of us. That despite routinely maintained aseptic protocols the damned things were somehow getting inside the beakers and infesting meristems.

Somewhere in the threads about this at the rhodo group, there's an account of a small nursery in TN, the owner of which has figured out how to micro-propagate in her kitchen! She focuses on native deciduous azaleas apparently, but I wonder if that might be the future of preserving uncommon rhododendron cultivars and grexes and making them available to gardeners. DIY and small scale.

Where can I find this group? I’d like to follow it.

Oh sorry I missed that ctgardenguy. here it is...

https://groups.io/g/Rhodo/topics