I vote for root rot or aerial blight.

Thanks jean001a

What should I do? Stop watering the plant?
I am in California and temperatures get high
How many days should I stop watering the plant?

Is there any way to save it at all?
Now it is just left with less than 10 leaves compared to 100s a few days back

Green leaves are shading as well

There are number of root diseases, most of them types of water molds, that can kill a rhododendron with surprising speed. All of them flourish when the planting medium is overly wet and subject to high temperatures. Potted rhododendrons are especially vulnerable because heat can build up rapidly and drainage deteriorates over time even if it started out okay. Sad to say, this plant is not at all likely to recover no matter what you do.

Thanks for your response Even re-potting is likely to kill it? Can I take a branch out and try to grow it again because there are alive branches on the tree.
I cant just watch it die :( :(
I had specifically asked the question about if I can plant rhododendron in a pot when I bought it. The answer I got was, it is possible to grow in pots

This post was edited by Madhura on Mon, Jun 2, 14 at 21:47

You can try rooting a cutting. There's nothing to lose even though success is not very likely unless the cutting is in the right condition to produce roots. Firm, but still flexible, etc.

Rhododendrons can be grown in pots, but you do have to pay very close attention to drainage and avoid heat build up. The water molds infect the roots and clog the normal channels through which the plant receives water and nutrients.

Another alternative to just watching it die: Trim off all the obvious dead material and repot in fresh planting medium that provides very good drainage. There's not much reason to be optimistic about the chances for long term survival, but the desire to do something is entirely understandable.