My neighbor's son bought her some mulch on Mother's Day and installed it. With the wet and hot and humid year we've had here she has a fungus growing on top of it probably 6-8" long and 4-6" across, a yellow color that looked like spilled paint.It was tacky to the touch. She left the house one day at 4:00 pm and everything was fine. She returned at 8:00 pm and had 4 of these spots growing ( a span of 4 hours) one of which was creeping up the foundation a couple inches. She's a retired nurse and a little fussy and is out there every day with latex gloves. She removes what she can with a pooper scooper and gets the rest by hand. It got into a climatis plant and looks like it may kill it. After a week I was there again and one of the spots turned a brownish color and looked like the spray insulation you get at the hardware store, a couple inches thick as well. Does anybody know what this is and will we be able to get rid of it without replacing the mulch?