An evergreen is a note I’d defend in a conversation. The claim has stabilised. The examples are concrete. The phrasing has been edited enough that I don’t wince when I re-read it. Still not “done” — nothing in a garden is — but load-bearing.
If a seedling is “I just had this thought” and a budding note is “this thought has held up so far,” an evergreen is “I’ll stake my reputation on this.”
These are also the notes most likely to get linked from elsewhere — the trunks the rest of the garden grows around.