I planted a Gomer Waterer rhododendron a few weeks ago.. Please see the attached picture. Quite a few of the older leaves have developed "burnt" areas. The bottom of the leaf has the same areas as the tops, but otherwise are clean. Some of the new leaves are normal but some are misshapen. Could this be because the plant was allowed to dry out before I received it or is this a disease?
It is very possible this is sunburn or leaf scorch. It doesn't look like disease (though you can send us a photo of the new misshapened leaves.
Damage may have resulted from poor watering at some point, but we cannot say for sure. Keep it watered for at least 2 years during dry periods--including spring and fall. Watch your rain gauge. Soil should be damp, not sodden. Plants like about 1" of rain a week.