My houseplants (amaryllis and various other tropicals) have all acquired a
yellow fungus (looks sort as if I sprinkled sulfer powder) on the the soil
around them. It could not be killed by cinnamon, what I usually use to
treat mild fungal problems. I have not been overwatering them, rather the
opposite, I have been letting them dry out until they droop and then
watering them. Any ideas what this is and how to kill it without killing the
plants? I was just about to put them outside with my annuals but will pitch
them rather than loose the lot if I can't get rid of it.

mm