Okay, so I prepped my garden area last October. Took out three trees, including the stumps. Sprayed Roundup on the Bermuda twice, six weeks apart. Rototilled and generally leveled, then covered in very heavy black plastic to try and eradicate the bermuda as best I could.
On top of the plastic, I set up two large sawhorse tables, also covered in black plastic, on which I have been container gardening a winter crop which has done very well. Each table has maybe 25 or 30 containers.
About a month ago, as I was going back and forth between the tables, I noted a small hill where there had not been one before. It had been raining and there were new puddles all around it with a high center. It was soft, like the surrounding dirt, but it was something new. I guess it was about 2x2 feet.
Today, it is about 3x8 feet. Still soft, taller by half. I can't pull the plastic back to look at it because of the large tables, and it's still a month or so before I am okay with cutting it away to look. It feels like dirt, so I guess it is. But what is bulging it up like that, and making it so much larger? It is about five feet from where the large ash tree was taken out, but we filled in the hole and tamped it down, so its not that the surrounding area is sinking.
I am thinking radiation mutated gopher.
On top of the plastic, I set up two large sawhorse tables, also covered in black plastic, on which I have been container gardening a winter crop which has done very well. Each table has maybe 25 or 30 containers.
About a month ago, as I was going back and forth between the tables, I noted a small hill where there had not been one before. It had been raining and there were new puddles all around it with a high center. It was soft, like the surrounding dirt, but it was something new. I guess it was about 2x2 feet.
Today, it is about 3x8 feet. Still soft, taller by half. I can't pull the plastic back to look at it because of the large tables, and it's still a month or so before I am okay with cutting it away to look. It feels like dirt, so I guess it is. But what is bulging it up like that, and making it so much larger? It is about five feet from where the large ash tree was taken out, but we filled in the hole and tamped it down, so its not that the surrounding area is sinking.
I am thinking radiation mutated gopher.
Get the mallet out! 
