In the summer daytime I noticed ants hanging around on the leaves. Usually ants are a sign of another insect because ants cultivate aphids and other sucking insects that secrete sugars. But I didn't see any other bugs. Research says that some Cassias have extrafloral nectaries which attract ants probably to deter herbivores.
It is a beautiful plant flowering in autumn. But after it's done blooming, I'm going to cut it back and move it to a better spot. Wish me luck!