We are attempting a manual root collar excavation on our 51” burr oak, that has been declining over the past eight years that we have lived here. It is slow going, and appears that the tree has been buried for a very long time. There is a layer of crumbly weird rock, ceramic & glass shards, and rusted metal pieces that make us think the burial happened when the house was constructed in 1920. The bark under the surface is almost smooth. Last year a chicken of the woods appeared by the base of the tree, so we are doing what we can to help it out, but the more I Google, the more disheartened I get. We had an arborist check it out, and we did a crown clean out over the winter and are debating their fertilizer treatment, but we just can’t afford the price tag that comes with their air spade excavation. I’m including pictures of what we’ve gotten done so far, over the course of several days. Should we keep going deeper? Or are we fighting a losing battle here?