While picking up trees for a client I saw a neglected semi-dying redwood tree on the end of a row. I asked about a discount on the tree for the condition it was in. They responded by letting me know that it was going to be thrown away and that I could take it for free.
I couldn’t see much of the base as it was buried inside the container, but once I cut down the sides I was pleased with the interesting base it provided. Reverse taper, yes. Nonetheless this is something that can be a fun project from here on out for free. Here are a few more photos of it: