root growth

Hi Everyone, This is my first post on this forum--nice to meet everyone:) I live in Eastern Massachusetts, USDA Zone 6. An arborist planted a Hinoki Cypress in 2019 in the front foundation of my house and it has grown very well. Because I'd like to plant some tulips, I dig out some soil and...

I saw @leatherback mention in a video (don't recall which one, but I think it was about japanese maple) that he had buried the nebari. I believe the reason was to encourage growth. Is this a common technique? What are it's primary goals, just so I don't mis-state them? Are there specific species...

So this is probably an older method I just hadn't heard of based on the age of the book, but in Bonsai: It's Art, Science, History, and Philosophy by Deborah Koreshoff she talks about a few methods to creating new surface roots. Essentially, one method it talks about is drilling holes to the...