That's cool how you're finding what works. Unfortunately finding some of what doesn't is usually part of that. Even when you are using the right zone, an area as small as a suburban yard can have variations. Adding a pot to the equation is another variable.
You might find some candidates looking at the more hardy alpine plants. "Alpine" is a warning to me that plants would probably die of heat (& humidity) stroke here, plants that are found at higher elevations, in cooler, dryer climates. IDK why I didn't think of it to suggest to you before.
