Its first and only bloom this year.

We fertilized earlier this season with a time released fertilizer (sold by the hybridizer) designed especially for hibiscuses.
In return, we got lush green foliage in those plants all Summer long BUT not a single flower.
Finally producing merely a single bloom, this has been the only one of those plants so far to flower in 2023.

Last year https://pbase.com/britestar/image/172909300, this hibiscus (not fertilized by us)
bloomed her head off with day after day after day with multiple flowers for months.
Go figure.