I know that both Kalmia polifolia (swamp laurel) and Kalmia angustifolia (sheep laurel AKA lambkill) will grow in wet soil or even part-time very shallow water. IME both are smaller and less ornamental than Kalmia latifolia, mountain laurel, but mountain laurel likes moist well-drained soil. I think if your site is too wet for rhododendrons, it will also be too wet for mountain laurel.

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.

Agree that they are probably too wet. You don't say how long they've been planted there, but once a week watering is too much for them. The established ones around here went almost two years without rain or supplemental water and didn't even looked stressed.

great! i love winterberries! i have the perfect spot for winterberry holly (Ilex Verticillata) and already have an order on one. i think i will move the Mountain Laurel's location over to a less wet area in between the Eastern Red Cedar & pine. NHBabs - thanks for that map! it's been really helpful! i've been researching alot of the viburnums since you mentioned them last. what's your take on Nannyberry (Lentago)? i think i'm eyeing this one for that large semi-shaded area. it should do better than the Arrowwoods i think. i read the Lentago will have a better time beating V. Beetles. i don't have much hope sadly for the Arrowwoods i planted 2 years ago :-( although not confirmed yet. they just didn't leaf much last spring. a