I live in Maryland, near Washington, DC. I planted a 2 gallon azalea on the side of my house last fall, in September 2012. It is a Nancy of Robin Hill.

The plant did well in the fall, winter, and first half of this spring, in 2013. Even though we had a cool spring, it started to wilt in mid April. The wilting has continued without stop. None of the leaves have turned yellow, however - in fact, most are very dark green. Two or three leaves did turn black and die. I checked the stems and every one I cut a little to check is green, even the base. Mostly the azalea just seems slowly but increasingly wilting - or weak. I have attached a picture.

The area I planted this wilting azalea is near others on the side of my house -- the closest two are 3-4 feet away - which have done fine. I did have two azaleas of the same kind die in this particular spot - maybe due to too much water in the past or getting cut apart by careless gardeners. Neither thing has happened for this third azalea.

Any ideas on what could be going wrong? What should I do?