I have a leggy, presumably older rhododendron in my front yard that is looking sickly this spring - lots of brown leaves and dead branches. It is growing amid the roots of a creeping juniper and a whole festival of weeds and other unwanted things (burdock, mugwort, red deadnettle and porcelain berry, to name a few). I pruned off the worst of the dead stuff and tried to give it some breathing room, but the poor plant looks like it has just given up the ghost. Anything else I can do to save it?