Our azaleas seem to be dying one branch at a time. The leaves dry up and turn Brown on affected branches. Keeps going until the entire shrub is dead. We're down to the last one.
Harris County Texas azaleas
From the pictures, there may be a root rot affecting the movement of water and nutrients in the plant. Look at the base of the plant and see if there is a cracking or splitting of the bark at the soil line. If so, then there is a fungal pathogen that is causing the roots to rot. This can be caused by over-watering, or the mulch piled too high or too closely to the trunk of the plant.
Thanks for the question.