All good advice above!
The cannas are way too much completion!
They and the banana looked burned in one pic, sun I assume?
It's tough to burn those 2 if they are established! Unless they get way too dry, if that happened it didn't help!
As mentioned, easy on tossing it scraps, they are hungry but they can't eat that stuff! And it'll attract baddies..
I'd dump a big load of wood ash and old charcoal on it, not kings ford briquets if you can help it.
And like Evan said, lots of fert!
If you don't mind paying for it, it's hard to argue with the results if banana fuel, but there's cheaper options too!
I might suggest some other types too, none you mentioned ate super tough, veluntina is a pretty good grower but not always dependable...ice creams are wimpy outta the tropics, namwa is better but still not the best, as you know yours is probably namwa...
I'd go for some dwarf cavendish or some non fruiting ones like basjoo, both are pretty durable, aside from high winds and drought...
