Hibiscus rosa-sinensis, more commonly known as tropical hibiscus, is a perennial flowering shrub prized for its large, colorful blossoms. Native to tropical Asia, hibiscus grows best in U.S. Department of Agriculture plant hardiness zones 9 and 10. In ideal growing conditions, tropical hibiscus can reach heights of up to 12 feet and produce 8-inch-wide blossoms all year long. Despite all of its showy beauty, tropical hibiscus requires surprisingly simple care.
Difficulty: Moderately Easy
Water tropical hibiscus once or twice a week to keep the surrounding soil consistently moist to a depth of approximately 4 inches. Apply supplemental irrigation to the soil directly, as wetting the foliage of your tropical hibiscus on a regular basis can encourage the development of foliar disease.
Fertilize your tropical hibiscus once a month from April to September to provide it with the nutrients it needs for healthy growth and flower development. For best results, fertilize with a water-soluble fertilizer that has been specially formulated for use with flowering plants.
Prune one-third of the old growth from your tropical hibiscus annually, in the early spring, to promote healthy, vigorous growth. Remove diseased, damaged or dead branches from the tropical hibiscus, as needed, to maintain its health.
Monitor tropical hibiscus for problems with common insect pests such as aphids, scale and mites. Rinse pests from affected plants with a high pressure garden hose; do this in the morning to ensure that the foliage of your tropical hibiscus will be dry before nightfall.
If grown outdoors in USDA zones 7 or 8, tropical hibiscus must be treated as an annual.
Use sharpened and sterilized pruning shears or loppers when pruning your plant to help prevent the spread of damaging plant diseases.