While in Germany in June, we visited a Bird Park in Hannover. The rhododendrons were fabulous. I've wanted to purchase one that I believe is called Azalea Persil, but I can't find it in the US.
Does anyone know where I can find it?
'Persil' is a Knapp Hill/Slocock deciduous azalea with a white flower with a beautiful golden-yellow blotch. It is quite popular in Europe. I don't have any idea of where to buy it in the US or Canada.
You might try Northern Hi-Lights, a deciduous azalea that should do well in zones 4-5. Here is a photo:
Here is a link that might be useful: Deciduous Azaleas from Roslyn Nursery
I have Northern Hi-lights, and would recommend it. It has a lovely scent and as rhodyman's photo shows, it has beautiful flowers. It also has reddish fall color, and one of mine has recovered nicely from my husband mowing over it with the brushhog! Overall a great cold weather deciduous rhody.
One problem for you with the one in Germany is that it might or might not be hardy for you.