Gardeners enjoy growing hibiscus shrubs because the plants are very hardy and can handle a wide range of growing environments. The plant is best recognized for its floppy, bright flowers and dark green leaves, which can make for an attractive hedge or accent shrub. Give the hibiscus the care it requires to encourage fast, vigorous growth and lots of flower blossoms.
Test the pH levels of your gardening site with a pH testing kit from a garden store. Hibiscus plants grow best in a pH ranging between a high of 6.5 and a low of 5.5, and anything else can cause nutritional deficiencies, according to the University of Florida. Ask your regional cooperative extension office (see Resources) what amendments, like sulfates, phosphates and lime, are using in your area to adjust soil pH levels.
Fertilize the hibiscus plant once a month during its spring, summer and fall growing season. Louisiana State University recommends using a 12-4-18 fertilizer. Spread the fertilizer around the hibiscus shrub according to its labeled instructions, since fertilizer potency varies by brand.
Irrigate the hibiscus plant weekly with enough water to soak the soil to a depth of 18 inches, according to the University of Florida. Pile 3 inches of mulch around the shrub's base to help conserve moisture between waterings.
Defend the hibiscus shrub against insects. Serious pests include aphids and whiteflies. Spray the shrub on an as-needed basis with an all-purpose horticultural oil solution, available from most garden stores.