@Gemma I know what you mean about MINT! I have some in my turtle habitat — it’s great for them because it grows fast and gets very full (plus it’s edible so offers them forage). BUT! I had to yank it last year as it was literally taking over (and I’m still on “mint patrol” — baby mints popping up everywhere)! Great for the turtles (they love places to hide), but I couldn’t stand it. I am letting some grow in a couple of areas, but plan to keep it contained! It’s OK as long as I don’t let it go free-range! I had some chocolate mint at one time, as well —
that was the worst of all! Had even planted some of the chocolate as a marginal around the pond — uh, uh — NEVER AGAIN! I’ve never had the kind specifically called “aquatic mint.” But I do have a few sprigs from whatever was invading the turtle habitat growing among the rocks as a marginal. I’m keeping a close eye on it. So far it seems to be behaving so will give it a chance. It does have lovely purple flowers in late summer!