What an awesome post @notconvinced. Our little mound wasn't nearly as well done as what you just built.
For us to dig 18 inches will take a lot og effort without machines... very rocky!!! But I guess we could build it on the ground ans bring up thw dirt around it. Or just dig as deep as we can and just go with that!
Thanks for the detailed post I am inspired.
You are very welcome. Have you dug very deep to check it out?
I've volunteered a lot down in Missouri, where the soil is super rocky mixed with sandy clay everywhere. While digging post holes I realized that around 8" down the rocks thinned significantly.
Yeah so far I have dug in many different places... planted an apple tree the other day only had to dig in two different places to find a place betwwen boulders. I hope it grows.