My Hibiscus are several years old, grown in pots, wintered indoors and left outdoors on a west facing balcony once the weather is warm. This year I have blooms but no leaves! What is wrong, and how can I fix it?
The best thing to do is just to give it more time, maybe a little fertilizer too if you have not done that yet this year. This normally happens when there is not enough light. The plant may have broken dormancy a bit too early indoors, so it formed its flowers but not leaves - then you moved it outside and the flowers were set to go but the leaves had to catch up. It should correct itself in a few weeks.