How to Plant and Grow Tropical Hibiscus

Grown for their large and showy blooms, tropical hibiscus (Hibiscus rosa-sinensis) shrubs add serious flower power to any garden. Though they aren't hardy where it freezes, these plants will produce plenty of blooms throughout the season and can be overwintered indoors. There are dozens of colors, plus single- and double-flowered varieties.  

With so many available colors, you are bound to find a tropical hibiscus that will work with your garden palette. The only color you won't see in this tropical plant is true blue. These distinctive-looking plants bloom almost the whole season as long as they have plenty of sunshine. Many types even have bi-color blooms or other special features like frilly petals.

Where to Plant Tropical Hibiscus

Select a location that receives full sun and has well-draining soil. Tropical hibiscus shrubs cannot tolerate any freezing temperatures and are hardy only in USDA zones 10 and 11 and the warmest parts of zone 9. Tropical hibiscus can be grown outside in containers for the season and then brought inside for the winter in cooler zones. However, cold-weather gardeners may find that hardy hibiscus is a better match for their climates.

How and When to Plant Tropical Hibiscus

The best time to plant tropical hibiscus is in early spring. Before planting nursery-grown plants, amend the soil to be organically rich and well-draining. Dig a hole slightly larger than the anticipated size of the rootball. Remove the plant from the container and loosen the roots. Set the plant in the hole at the same depth it was in the container, being careful not to bury any part of the stem. Backfill the hole with the amended soil and water the plant.

Tropical Hibiscus Care Tips

Hibiscus are easy-to-grow plants that require very little maintenance.

Light

Full sun exposure ensures tropical hibiscus plants develop the most flowers and have strong branches. In the hottest part of the day, the plant benefits from some afternoon shade.

Soil and Water

Tropical hibiscus grows best in well-drained soil that is organically rich with a slightly acidic to neutral pH of 6.0 to 7.0.

During hot summers, water tropical hibiscus shrubs daily to prevent them from dropping any flower buds due to heat stress, but be careful not to overwater.

Temperature and Humidity

Tropical hibiscus thrives in the 60°F to 85°F temperature range. If the temperature falls below 50°F, growth and blooming slow down or stop. A freeze kills the plant. Humidity should be 50 percent or higher.

Fertilizer

At planting time, apply a balanced granular fertilizer, such as 10-10-10. After that, and throughout the growing season, tropical hibiscus shrubs need more nitrogen (N) and potassium (K) than phosphorus (P), so a fertilizer with a 12-4-8 analysis is best for regular fertilization. Follow the product instructions for the proper quantity.

Pruning

The branches may need some pruning to shape the plants and prevent them from being sparse. Do this in the spring, right before the heat of the summer, to encourage a new flush of growth.

Potting and Repotting

Tropical hibiscus shrubs make wonderful container plants. Plant them in a large, well-draining container filled with general-purpose potting mix and use a slow-release fertilizer. You can also water the plants with a general-purpose fertilizer or one formulated for blooming plants every other week or once a month to promote blooms.

When grown indoors, the cooler temperature and lower light inside slow these plants down, so don't plan on blooms during the winter. If they try to bloom, you may find it beneficial to pinch the buds off so that the plants focus their energy on surviving and not blooming.

Pests and Problems

Like many garden plants, tropical hibiscus shrubs can attract the unwanted attention of aphids, mealybugs and scale insects, which can be controlled with insecticidal soap or neem oil.

They sometimes are the targets of caterpillars. The best solution is to pick off the caterpillars and drop them into a jar of soapy water.

How to Propagate Tropical Hibiscus

The easiest way to propagate tropical hibiscus is with stem cuttings. In summer, take 8-inch stem cuttings from a mature plant, making the cut immediately beneath a leaf node. Remove all foliage and buds except the top two leaves and dip the bottom of the cutting in rooting hormone. Fill a pot with moist perlite and insert half the cutting into the planting medium. Repeat the process with several cuttings to increase the chances of success. Cover the pot with a plastic bag to retain humidity and place it in a warm place, preferably between 70°F and 85°F, which might require a heating mat. Check the pot regularly and keep the planting medium moist. When new growth appears, which can take up to two months, the cutting has rooted. The resulting young plant will be an exact clone of the parent plant.

New Innovations

Research has been going on in the world of tropical hibiscus. Whether in the novelty domain, where people are breeding specifically for interesting colors and patterns, or in the wholesale plant trade to make overall improvements, there have been many developments. A new series called the Hollywood Series features great new color options on dwarf plants perfect for containers. These varieties also feature blooms that stay open several days longer than original hibiscus breeds.

Types of Hibiscus

'Amazon Queen' Hibiscus

Hibiscus rosa-sinensis 'Amazon Queen' shows off extra-large beige flowers with ruffled edges. It can grow 8 feet tall and 4 feet wide. Zones 10-11

'Bonnie B' Hibiscus

Hibiscus rosa-sinensis 'Bonnie B' offers large red and lavender blooms that fade to orange and yellow at the edges. It can reach 12 feet tall and 8 feet wide. Zones 10-11

'Gator Pride' Hibiscus

Hibiscus rosa-sinensis 'Gator Pride' is a stunning selection with 6-inch-wide, lavender-blue flowers that blend to apricot-pink at the edges. It grows 10 feet tall and 6 feet wide. Zones 10-11

'Goin Steady' Hibiscus

Hibiscus rosa-sinensis 'Goin Steady' offers huge white semidouble flowers with bright pink centers. It can grow 8 feet tall and 4 feet wide. Zones 10-11

'White Wings' Hibiscus

Hibiscus rosa-sinensis 'White Wings' is an old but classic variety with white flowers that have bold red centers. It grows 15 feet tall and 8 feet wide. Zones 10-11