You need to understand what constitutes quality content.

No, I don't. And I can't. It is impossible to have global or universal criteria to quality. This itself is a communication process. As I mentioned above: It's NOT me to decide what is quality!

it is interesting to talk about how the garden was loosened and what grew there.

Yes, it is! I never have been on the way to deny that.

And this is also valuable, there is a paradox in this, but it is true.

This is indeed valuable, but there I cannot see a "paradox". I'm sure there is no such thing.

Writing on my garden can lead to a quality post.
Writing on philosophy can lead to a very poor post.
It's not the issue or theme, it's the writing itsel, it is the forming of my thoughts and words while writing.

"Hello, Sokrates is my hero, and I like also Heraklit!" would be a very poor post.
"While working in my garden, I detected some new plants which before never seen in my area." could be the beginning of a very good post on changes in natural life of plants.