I am a professional gardener. What are the most realistic things to put in a fantastical garden?

I work in horticulture and have been working in a botanical garden for the past 3 years. I love worldbuilding, and I want to work on a new project, but I'd like to hear your thoughts: what can be in a fantastical garden that is really cool but not unrealistic? I really want to avoid the kind of tropes that make me roll my eyes in movies and shows, like having two plants from different continents thriving in the same place, or having the seasons simultaneously represented by flowers AND literal snow and sunshine, or having mossy waterfalls in a desert. I know that a garden can be anything you want it to be, but I want to make sure that the things in it are realistic, even if the plants themselves aren't. Does that make sense? So I really want to hear from you, what should I keep in the fantastical garden and what should I avoid?<br><br>TLDR: I am a professional gardener. What can be in a fantastical garden that is really cool but not unrealistic?