Why Do Fresh Woodchip And Potting Mix Turn Mouldy And Repel Water?

Question: “Dear Jerry,┬áIn the last year, I have had a soil problem that looks normal on the surface, but when you dig into the mulch, it is grey and looks like a fungus has taken over. The soil smells mouldy, (maybe anaerobic?) and when I water, the water just runs off, not in. This problem…