Mountain Laurel can withstand full sun in many climates. In your particular case, however, I think the heat will be a serious problem. You're in a warm climate zone, the kalmia will receive direct sun all day long plus the reflected heat from the wall behind it. In the height of summer if not before, I do think this will be just too much for this species. You'll very likely have problems from winter sun as well. It's also not a great choice for providing screening, either. It's naturally quite a slow grower and the small leaves do not provide much in the way of the kind of cover you're looking for. It would be fine to move it now. Many shrubs can be kept to the size you want by pruning. I'd ask the nursery for their recommendations.

Very mysterious! I'd call Broken Arrow Nursery in Hamden, CT, as they have introduced so many of these mountain laurels to the trade -- possibly even the 2 varieties you mention. Ask for someone on their Hort staff.... Wish I could give you more input than that, but I just don't know! Good luck, ML

Congratulation! You have a lot of courage to plant it in your z4 and you won! Take it from Connecticut's kalmias lover, where they grow like a weeds. Here are few pictures of another kalmias you might want to consider in a future, Carousel Keepsake Despite the popular belief that kalmias are shade lovers (they are shade tolerant, that's it) kalmias if planted in a too shady location will not bloom as good as those that are planted in part to full sun. The main trick is to give them protection from the WINTER sun to avoid dissecation of the leaves. In their young years they need to be protected (as you did) from the cold AND from the sun, but later on, winter sun will be your worse enemy. Use wilt-pruff and/or burlap wrap/screen. Water well before ground will be frozen, but do not overwater in a summer (especially if planted in a shade), cause Phytophora ramorum fungus while being harmless to overall plant's health could seriously ruin aesthetic appearance of the leaves. Good luck! Now I'm convinced that I could grow camellias!

Ouch! Many years ago my grandparents had a mimosa tree struck by lightning and it split to the ground as well. They cabled it back together (upper branches) and put tar (this was in the 50's, so didn't have pruning paint back then) around the wound. It eventually grew back together and lived for many many many years. They left the cabling in the canopy for support. So the same thing might work on your mountain laurel. I think cabling would work better than a cast.