This is my first post here. Not sure if its the right forum area, but I am hoping to get some suggestions on how to go about this strange issue I have. About 10 years ago we had a large tree removed in our back yard and the majority of the stump was removed. We then had stonework done. In the circle planter that is in the same location where the tree used to be we started getting a bad fungi growth that I tried to remove many times over the years. So I finally decided to gut the area, remove the large fungi mound and do it right with some dirt fill , black plastic and then top layer small stone pebbles.
After removing the fungi the area became very loose and started to cave-in in some spots, including where one of the stones fell through about a foot down. When we got the stone installed I could have sworn they installed these stone flat on ground dirt, but now there seems to be some hollowing going on and the only thing I can think of is termites are devouring the left over root system from the tree. My dog was digging and barking around the area one day and he only does that if hes chasing a rodent or something so I am kind of concerned rats are using this as a hideout. The whole area of the stone work used to be flat but now there are some areas where it dips a bit. I was planning on just digging the most I can of this old rotten soggy roots out that I can. It's strange that these chunks of root are very moist as our land tends to be very dry and dusty here in southern California. Its clearly got termites on it (no experience with termites like this before) I was thinking of filling it with dirt. Is that the best action to take? I cant really spray anything poisonous down there to kill the termites because I have a dog. Any suggestions are greatly appreciated thanks.
