Too much rain or something else?
Attached are 2 hibiscus potted plants purchased 2 weeks apart from 2 different nurseries. They both sit on our sunny deck in Kingsville, MD. The first picture is the happy orange-flowered hibiscus that is doing great. The last 2 pictures show the problem plant. The buds did open, have all dropped off and now there are no new buds. Some leaves are yellow and many green leaves have black spots on them. I see no apparent aphids, so what could be going on?
Baltimore County Maryland
Your problem is probably a leaf spotting disease which can be related to all the rain.
Clip off any yellowing and spotted leaves and throw them away in the trash. When you water, water from beneath to avoid the leaves staying wet for long periods of time.
It's not uncommon for hibiscus to drop leaves and buds when stressed, and some cultivars are more likely to do it than others. As it warms up they will be happier.
We can't see, but we are assuming that your colorful pottery has drainage holes so the plants don't sit in water, right? If not, either repot or raise the inner pot up on blocks.