- A tropical species of plant, hibiscus is both drought-tender and frost-tender. Planted outdoors, it requires temperatures of no less than 55 degrees Fahrenheit during the day, according to the University of Minnesota site. Colder temperatures can cause the buds to fall from the stems. Hibiscus grows best in daytime temperatures of 65 to 75 degrees Fahrenheit. When growing as a houseplant, avoid placing them near radiators, near drafty windows or other areas where temperatures can fluctuate.
- Hibiscus require large amounts of light to thrive and produce their large, trumpet-shaped flowers. Place plants where they will receive at least four to five hours of bright, direct sunlight each day. Without sufficient light, these plants will fail to produce blooms. If planted outdoors in shade, trim nearby plants to allow more light to reach the hibiscus.
- Being a tropical plant, hibiscus prefers conditions of high humidity in order to thrive. Lack of sufficient moisture in the air can cause. If growing hibiscus indoors, mist the plant frequently or place the pot on a layer of rocks in a tray full of water to increase the ambient humidity. Leaves can frequently fall off the stems when the plant goes into a rest period. Prune back the branches and reduce the amount of watering. Allow the plant to rest for several weeks. It will soon be ready to grow new leaves and bloom again. Excessive watering and drought will also cause buds to fall from the plant.
- Hibiscus can develop insects problems, including aphids, thrips, mealybugs and whiteflies. These pests often attack hibiscus that are in areas without good air circulation around the plants, according to University of Florida horticulturalists D.L. Ingram and L. Rabinowitz. Often these pests will lay eggs in the folds of the buds causing them to droop and fall from the stems before blooming can occur. Treat the plant with an chemical insecticide containing acephate or an organic insecticide that contains neem oil. Hibiscus is sensitive to many insecticides. Spray in the early morning rather than in the heat of the day.