Tropical hibiscus plants should be kept consistently moist, so water whenever the top inch of soil is dry. (Stick your finger in the soil to check.) Containers may need to be watered 3 to 4 times weekly at the beginning of the summer and daily toward the end of the summer as the plants grow.
The best fertilizers for hibiscus are high in potassium (K), have a medium amount of nitrogen (N), and are low in phosphorus (P). such as NPK 10-5-20. Fertilize every 2 weeks in the growing season using a liquid fertilizer or every 8 weeks using a slow-release fertilizer
a hibiscus plant needs about 6 hours of full sun per day in order to bloom to its fullest potential. It will still grow perfectly well in partial shade, but it won't fill in as fully or bloom as spectacularly. The more light a hibiscus gets, the better it will bloom, up to a point
Hibiscuses like temperatures between 60-85°F. If temperatures are below 50°F, most growth and blooming will stop and flower size will be smaller and deformed. A freeze will cause the plant to die so be sure to move your plant indoors before the first fall frost. Hibiscus is also very sensitive to extreme heat.
Determine if the hibiscus truly needs repotting by checking the drain holes of its present container for protruding roots. Loosen the plant in its container and lift it up to get a better look at the roots. If the roots are packed tightly together or form a pot-shaped, tight circle, the plant needs repotting.