This is an old practice. A local Reading, PA, nursery center got its plants from a well known nursery in Oregon and just took what they were sent. They were sent beautiful plants in full bloom, but many of them were not hardy. I questioned them about this practice, and they said that it led to more repeat business, because people were willing to try new things and would rather have tried them and failed than never tried them at all.

I agree with you, that this practice is not ethical, especially when they fudge the hardiness ratings.

Regarding Blue Baron:

Brooklyn Botanic Garden calls Blue Baron a signature plant and gives it a USDA Z5-8 rating.

The Massachussetts Chapter of the ARS describes it as a Z5 plant.

Hank Schannen and Harold Greer don't list this plant as in their nurseries.

Peter Cox with his usual candor describes Blue Baron as "Not very heat or sun tolerant and needs good drainage, so may be of limited value." So apparently hardiness is not its Achilles heel.

Blue Baron is like Purple Splendor and Capistrano when they came out, everyone want to have a chance to kill one. Fortunately, in colder hardiness zones, there are micro climates where these plants thrive. Also, some people have the good fortune of coaxing a tender plant to get a zone or two hardier than other people. Most rhododendrons take a number of years to attain their hardiness. If the natural chain of events in a garden lead to progressively colder, tougher winters, a person may end up with a hardier plant.

I'm really annoyed with my Blue Baron's... I went to a reliable/trustworthy nursery with a 1 yr gaurantee on shrubs. I have 2 blue baron that has been through 2 winters now and I've seen 1 bloom on one of those. I have another one that went through it's 1st winter and it's alive but doesn't look very good. Lesson learned about checking the hardiness zone on the tags. :( I didn't realize it was only hardy to zone 4 when I purchased them. I thought I was doing good to know I needed shrubs that were good for part shade.

I find it really unethical for nurseries to sell shrubs that are not hardy for the area. It's just not right. It's not like I went to Home Depot. I don't want to deal with digging them up & trying to return them. I have 1 that may be just under/over the 1 yr mark. I think I just need to wrap them next winter with some burlap or something to protect them some. Not ready to give up on them just yet even tho maybe I should try something else. :(

I've also found Blue Baron to be a very poor bloomer. Finding the right balance between enough sun to promote bud set and enough shade to protect the plant in winter is a challenge. Burlap may help, but I don't think this variety is really worth the space it takes up, especially in Z5. Far better is Blue Ridge. This variety was very hard to find for a time, but seems to have been rediscovered by a number of nurseries. Iffy in Z5, but solidly reliable down to -10.

Well I fell for two Blue Barons at a nursery on Cape Cod. Hoping they do well, but my expectations have been dashed. I just put them in the ground today.

Cape Cod might be one of the few places on the east coast where they will thrive, if situated to their liking.