I grow several mints around my pond; all in containers and I watch them to be sure no stray shoots escape. I have Chocolate (my favorite) Pineapple, Lemon, Orange and Grapefruit (above). I have heavy clay soil so I have planted Cat Mint and Apple Mint to disguise my pond pump and wiring. Even in the clay I still have to pull it up when it creeps out of bounds.
One other "could be" pest is a beautiful ornamental grass called Moudry. It is only about 2 feet tall and has wonderful dark purple blooms in fall and is in the Pennisetum family of fountain grasses - perfect for a small garden - not! It reseeds everywhere! Those flowers drop their seeds. The only place for it is a section of garden that you don't mind being covered with Moudry. I actually put it way in the back corner of my yard where I couldn't get grass to grow and had difficulty getting in with the mower. Perfect!
Post a comment and tell us about your favorite (or not so favorite) invasive plants.