I have five mountain laurels that I bought 1-2 years ago. Here's the rundown:
1. Mountain Laurel in dry-ish field near large white pine - This one's new leaves are red. I think it may be a cultivar, but I can't remember the name. It's doing OK, but growing slowly. Bought at about 1 foot tall.
2. Mountain Laurel in moist-ish shade garden - It's the brother of the laurel in the field. It seems to like the extra water AND being sheltered on 3 sides. Growing faster. I dug it up and moved it from the field last Fall.
3. Three Bigger Laurels - I planted two 3 ft laurels in my shady side garden. I also have another one that I recently moved to my new Shade garden. All three all had tip browning! I think it may have been a fungus (look this up, Mt. Laurel's can get a couple of different diseases)...either that or their soil dried out before I bought them. Now, all three have LOTS of new light-green leaves. Thank God for all the rains we've been getting.
In general.
The first year I transplanted my mountain laurels, I gave them generous water once a week. I transplanted all in Autumn...except for the one I transplanted to my NEW (excited) shade garden a couple of weeks ago. Note, after planting you need to water deeply once a week (or as needed depending on heavy rainfall) until the ground freezes.
After planting, I mulched around each plant with pine bark mulch and/or pine needles. Basically, I followed the directions for planting...dug a big hole blahblahblah...but I didn't use any soil amendments.
I planted the shrubs a tiny bit above grade and then put mulch around--but not touching--the trunk.
Finally, I believe Mt. Laurels like acidic soil.