Answer: The key to knowing the health of your hibiscus is the amount and color of the new growth. Hibiscus will drop their older leaves, which turn yellow prior to dropping. As long as the yellowing leaves are throughout the canopy (rather than from just one branch), nothing is wrong with your hibiscus. Flowers are produced on new growth and hibiscus flowers best when the temperatures are warm. You can try pruning the hibiscus back to encourage lots of new (flowering) growth, and also feeding with a bloom booster (low nitrogen, high phosphorous and potassium). Best wishes with your plants.
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