A chap for whom I do gardening work has a lot of azaleas. All of these seem to be affected by the grey/white fungus/lichen/whatever it is shown in the pictures below. He's concerned that the stuff is threatening the well-being of the plants (potentially fatally), and since I don't know what the stuff is or what it does, I ought to take it seriously.
It looks like a lichen at first glance, but then lichen takes years to grow and this stuff seems to have appeared over a short space of time, as you'd expect from a fungal bloom. It doesn't affect the leaves, but seems mostly attracted to forks in the plants' branches.
If you can tell me what the growth is called, what harmful effects it can have, and what can be done to get rid of it, I'd be much obliged.
Steve :)
