Are you sure they were adequately winter hardy for your zone? Zone 6 is somewhat marginal for most evergreen forms.

I take a tablet or phone with me to look up plants when I am at the nursery or big box store since I have been burned a few times as far as size and hardiness given on plant tags. In my area I have seen many zone 6 plants sold at big box stores, so it is never safe to assume that they in particular will sell only hardy plants since I am in a cold zone 5. There is quite a range in hardiness in evergreen azaleas.

Do you have a variety name? I honestly haven't found any evergreen azaleas hardy to my area where it gets between -15 and -20 every winter at least for a bit, and colder than that sometimes, and I tried the hardiest rated I could find. Even if they survived and were root-hardy, the top of the plant was killed back to the snow line; ugly. My soil is ideal for rhododendrons and azaleas (acid, evenly moist, well-drained) and mine were in a good amount of winter shade which helps evergreens in areas with frozen soil. So I would doubt the veracity of the tag info which will often lump all of zone 5 together as hardy to -20, even if they are only hardy to -15. There may be other issues for these particular plants such as poor drainage in that part of your yard or more winter sun in that area or even that the plant arrived with root issues that are only now showing up. Cold hardiness is only one factor that influences survival of a plant and the care given at a big box store may or may not be ideal for the plant's long term health.

The purpose of plant tags is to sell you the plant, so IME the information is often optimistic in some information. For instance, shrub size is often given at 5 years. A couple of good sites to get a better idea of hardiness and actual size after a number of years is the Rhododendron database of the American Rhododendron Society and the Azalea database also from the ARS. For general shrub and tree info I usually use the Missouri Botanic Garden's Plant Finder.

Can someone tell me when the azalea caterpillar start. I am ready for them this year with the Bt spray. Mine are in full bloom now and couldn't be any prettier. I just hate to see them eat almost all of the leaves off.

Often Home Depot or WalMart has plants that are not even marked with a variety name. Sometimes, it's there on the pot or you just have to hunt for it on a tag. I'm with NHBabs. I always look up the variety (if it's marked) on my phone to see what the true hardiness rating is. Often you have to visit several sites and choose the one with the most conservative rating. I usually steer clear of un-named varieties. In my zone 7, we can usually grow most azaleas, but not all. So even I need to watch carefully.

In this case Enchanting Elegance could be a marketing name for a whole array of plants offered by a particular wholesaler or grower. Sort of like Garden Deput or Proven Winners.

'Karen' Azalea is evergreen and hardy to Zone 4: https://www.monrovia.com/plant-catalog/plants/64/karen-azalea/

Thanks, sah67. I will keep an eye out for that one and if I find it, give it a trial and report back. Some of the Gable hybrids tend to be hardier than many others.

NHBabs: I might pull back my recommendation of 'Karen'...even though it's supposed to be hardy down to Z4, the flower buds on mine took some serious damage this winter. The plant itself is alive and will probably put on new growth, but I'm not sure it will be a reliable bloomer.

Thanks for the follow up, sah67. That has been my experience with the several evergreen azaleas I have tried here, that only the parts underground or under snow do well and the rest loses all leaves and many of the buds. I am happy with the hardiest Rhododendrons along with deciduous azaleas here in the frozen north.

Yes: our 'Nova Zembla' Rhodo is doing fantastic, and we may try a couple of the 'Northern Lights Azaleas' this year since we don't have any deciduous ones right now.

I may also give 'Stewartsonian' Azalea a shot, since we're looking for a nice crimson red, and although it is another evergreen, I've heard good things about its hardiness...even more so than Karen. I'm still seeking some feedback from folks who have that one though.

Stewartsonian is the one I held onto the longest, hoping it would get better.

By "hoping it would get better", it sounds like it didn't do very well for you?

No, Stewartsonian didn't do well above the snow line. When the snow melted each spring, I had a foot or so of green leaves at the bottom, and at the appropriate time, a foot of flowers, but the top of the plant emerged from winter with bare twigs and never bloomed. Not an attractive look! A plant has to look really bad for me to dig it up since I have far more space than I could maintain as garden, but these were so homely that they were shovel pruned and composted.