Planting tree hole do's and don'ts

During a tree planting, we came across this one all chopped up. Notice the rotten core. In Portland, you need a permit from Urban Forestry to do any work on street trees in the strip. You also need to remove or grind stumps, especially before replanting. Roots travel wide. Alas, we did not plant a tree next to this fresh stump even though the owners wanted to.