I had a Western Red Cedar that had been "topped" by a previous homeowner in its early years and then grew topheavy and unsteady. I had to remove it before it fell on my house. I would like to plant a garden in the spot where the tree used to be. Some folks at the nursery said the soil is "toxic" in the areas around the former roots (quite a large area, I would imagine) and I need to excavate the area and have new soil trucked in. Others say that is not the case and I could just put down new soil and compost/test the soil and add nutrients as needed. Is Western Red Cedar allelopathy a myth? I've read some of the scholarly literature, but it's not in my field, so not sure I'm reading it correctly. Thanks!