stinky, sloppy mud
Last fall we had a large silver maple removed and the stump was ground. I dug out the wood chips and filled in the pit with a topsoil/compost mix (because I was getting that to make some flower and vegetable beds). I planted grass seed and am waiting for it to grow. Several yards away from that I used some of the dirt to fill in a low spot where there are some tree roots from that tree. The dirt over the large pit where the tree was is fine but at that one spot over the tree root the water does not drain well and the dirt I put there became a stinky slop with air bubbles. I've removed the stinky mud and am left with a hole in the ground with tree roots at the base of the hole. It's not a huge hole, maybe 2 ft in diameter, 3 inches deep. Is the dirt there becoming putrid because the tree roots are preventing drainage? How should I fill the hole? Or should I try to do something to the roots to create some drainage? What sort of chemical reaction was going on there? I've never encountered anything like it.