Help, I've combed the internet and can't seem to find out why some of my Hen and chick plants have a white-yellow marshmallow type stuff growing on them. Does anyone know what this even is so I can find a solution before it spreads to the remainder of the other plants? I did plant them over the top of a stump that has been decaying over 5 years and now there are mushrooms growing around this area as well. Area does get good sun in the morning. Help???