The Hibiscus Handbook: Expert Tips for Tropical Varieties
Tropical hibiscus plants are highly prized for their large, showy flowers. Some hibiscus varieties also produce sweet, floral scents. Although tropical hibiscus requires more care and attention than hardy hibiscus, they’re still extremely rewarding. In this article, we’ll discuss how to grow and care for tropical hibiscus.
Tropical Hibiscus: The Essentials:
| Plant Family: | Malvaceae |
| Genus: | Hibiscus |
| Scientific Name: | Hibiscus rosa-sinensis |
| Native Range: | China and other parts of Asia |
| Colors: | Various shades of red, pink, orange, yellow, and white |
| Characteristics: | Large, showy flowers with prominent staminal columns |
| Mature Height: | 6 to 12 feet (depending on the cultivar) |
| Flowering Season: | Year-round in warm climates |
| Growing Zones: | 9 to 12 (some cultivars can be grown in zone 8) |
| Sunlight: | Full sun to partial shade |
| Watering: | Consistently moist soil |
| Soil: | Rich, well-drained soil with high organic matter content |
| Fertilizing: | Balanced, slow-release fertilizer in spring and summer |
| Pests: | Spider mites, whiteflies, aphids |
| Pruning: | Prune in late winter or early spring to shape or control the size |
About Tropical Hibiscus
The Hibiscus genus contains hundreds of species that belong to the mallow family (Malvaceae). Most hibiscus flowers are divided into two types; hardy hibiscus and tropical hibiscus.
There are eight species of tropical hibiscus, with the Chinese hibiscus (Hibiscus rosa-sinensis) being the most common. Most tropical hibiscus sold worldwide are hybrids of Chinese hibiscus and one of the other tropical hibiscus species. It’s estimated that there are approximately 10,000 tropical hibiscus cultivars.
Tropical hibiscus thrives in warm, humid climates and is native to parts of Asia and Oceania. These fast-growing evergreen shrubs or trees can produce up to 2 feet of new growth each year. Many tropical hibiscus plants can grow up to 15 feet tall and approximately 5 to 10 feet wide.
Tropical hibiscus plants can bloom all year round in tropical climates. In other areas, these plants bloom from spring until fall. Some tropical hibiscus flowers are edible, such as those from the Chinese hibiscus. These beautiful blooms work well when added to salads.
What’s the Difference Between Tropical Hibiscus and Other Types of Hibiscus?
Hibiscus plants are divided into two main types depending on their required climate. Tropical hibiscus needs warm, tropical climates in USDA Zones 9 to 12. Hardy hibiscus can grow in cooler climates in Zones 5 to 9. Tropical hibiscus is evergreen in their respective climates, while hardy hibiscus is deciduous.
Both hardy and tropical hibiscus produce large, colorful trumpet-shaped flowers that only last for one or two days. However, tropical hibiscus plants have slightly more petite flowers than hardy hibiscus plants. Hardy hibiscus flowers are usually pink, purple, red, or white. Tropical hibiscus flowers come in more colors, such as orange, yellow, peach, or salmon.
Hardy and tropical hibiscus also have slightly different leaves. Most hardy hibiscus plants have medium green heart-shaped leaves, while tropical hibiscus produces glossy, dark green leaves.
Popular Types of Tropical Hibiscus
There are eight main species of tropical hibiscus, with the Chinese hibiscus being the most popular and widespread. Thousands of tropical hibiscus cultivars are also available. Here are a few of the most popular varieties:
- Hibiscus rosa-sinensis ‘Brilliant’ – This impressive tropical hibiscus cultivar produces large, bright red flowers. Each bloom can be up to 6 inches wide. This variety grows up to 10 feet tall and up to 6 feet wide.
- Hibiscus rosa-sinensis ‘Hollywood Rico Suave’ – ‘Rico Suave’ is a stunning tropical hibiscus with bright yellow flowers. Each bloom has a dark red center and ruffled, overlapping petals. It’s a compact variety that reaches approximately 5 feet tall.
- Hibiscus rosa-sinensis ‘Hula Girl’ – This Chinese hibiscus cultivar produces beautiful pale to bright yellow flowers with delicate, overlapping petals. In the right climate, ‘Hula Girl’ grows vigorously and blooms yearly.
- Hibiscus rosa-sinensis ‘Painted Lady’ – This elegant tropical hibiscus dazzles with large pink flowers with light pink veins and dark red centers. ‘Painted Lady’ grows between 6 and 10 feet tall and about 4 to 6 feet wide.
Growing & Caring for Tropical Hibiscus
Growing Tropical Hibiscus from Seed or Planting a Mature Plant
Tropical hibiscus can be grown from seed or bought and planted as mature plants. The latter is the easiest way of adding a tropical hibiscus to your garden. Just make sure to choose a variety that can cope with your climate.
Tropical hibiscus seeds should germinate and sprout within 7 to 30 days in consistently warm temperatures. 80 to 85ºF is ideal. Grow the seedlings in indirect sunlight and pot them up once they have several sets of true leaves. It can take between six months and two years for tropical hibiscus plants to flower from seed.
Where and How to Plant Tropical Hibiscus
Plant tropical hibiscus shrubs in areas that provide partial shade. Tropical hibiscus also needs fertile, well-draining soils that still hold some moisture. Planting your tropical hibiscus in a sheltered area helps protect it from cold or strong winds. You can also grow tropical hibiscus in pots.
Dig a hole that’s as deep and as wide as the root system of your tropical hibiscus. Place the plant in the hole so its crown is leveled with the soil’s surface. Fill in around the plant and gently firm down the soil. Water your newly planted tropical hibiscus thoroughly to help it acclimatize.
Soil Requirements
Tropical hibiscus shrubs require rich, well-draining soils that still retain some moisture. Tropical hibiscus plants also prefer neutral to slightly acidic soils with a pH range between 6.0 and 7.0. Add lots of organic matter, such as compost, to the soil to improve drainage while adding vital nutrients.
Sunlight Requirements
Most tropical hibiscus shrubs thrive in partial shade, especially in hot, arid climates. Provide a few hours of direct morning sunlight every day. In hot climates, the direct afternoon sun is too harsh for tropical hibiscus. In cooler areas, tropical hibiscus can grow in full sun.
Watering Needs
Tropical hibiscus plants need slightly moist soil, so water them whenever the top of the soil feels dry. In most climates, tropical hibiscus shrubs require 1 to 2 inches of water each week. In hot, dry summers, you may need to water your tropical hibiscus once or twice a day.
Fertilizing Needs
Fertilizing your tropical hibiscus helps it produce the best possible flowers. Feed tropical hibiscus with a diluted liquid fertilizer every two to four weeks throughout the growing season.
Temperature & Humidity Considerations
Tropical hibiscus shrubs thrive in warm, humid conditions in Zones 9 to 12. These tropical plants cannot tolerate cold temperatures or frost. Tropical hibiscus grows best in temperatures between 75 and 85ºF (23 to 30ºC). Most tropical hibiscus will lose their leaves if temperatures drop below 40ºF (4ºC).
Pruning & Deadheading
Deadhead spent flowers throughout the season to keep your tropical hibiscus looking good. In warm areas with no risk of frost, lightly prune tropical hibiscus in the fall. This stimulates new growth, which produces more flower buds. In colder areas, prune tropical hibiscus in the spring.
Propagating
The easiest way to propagate tropical hibiscus is through soft-stem cuttings. Take 4 to 6-inch cuttings during late spring or early summer and remove the lower leaves. Keep the cuttings warm and moist before planting them on.
Over Winter Care for Tropical Hibiscus
Tropical hibiscus cannot tolerate frost or cold temperatures. If you live anywhere below Zone 9, grow tropical hibiscus in pots. During the winter, bring your tropical hibiscus indoors until the spring. If tropical hibiscus is left out in the cold, they will lose their leaves and die.
Common Pests & Diseases
Common tropical hibiscus pests include aphids, mealybugs, and spider mites. Remove them using horticultural oils or insecticidal soap. Common tropical hibiscus diseases include gray mold and powdery mildew. Maintain good growing conditions to prevent diseases.
Best Companion Plants For Tropical Hibiscus
Companion plants are the best way to protect tropical hibiscus from pests and browsing herbivores. Companion plants can also attract pollinators and even enhance the appearance of nearby tropical hibiscus.
The most attractive companion plants for tropical hibiscus shrubs include alliums, coneflowers, coreopsis, delphiniums, and poppies. Crape myrtles make wonderful companion shrubs for tropical hibiscus plants. Plants like marigolds, nasturtiums, oregano, and rosemary can help deter or distract pests from feeding on your tropical hibiscus.
Growing Tropical Hibiscus FAQs:
What is the Hardiest Hibiscus?
Hardy hibiscus can survive outside Zone 9, while tropical hibiscus must grow in Zones 9 to 12. The hardiest types of hibiscus can tolerate winter temperatures as low as -30ºF.
Can Tropical Hibiscus Survive Winter Outside?
Tropical hibiscus cannot tolerate frost or cold temperatures. Even in Zones 9 to 12, tropical hibiscus need winter protection once nighttime temperatures drop to 40ºF. If left outside in the cold, tropical hibiscus will start losing their leaves.
Is Tropical Hibiscus an Evergreen?
Many tropical hibiscus species, including Chinese hibiscus (Hibiscus rosa-sinensis), are evergreen shrubs. However, evergreen tropical hibiscus may drop their leaves when exposed to cold temperatures.
What is the Lifespan of a Tropical Hibiscus?
Tropical hibiscus shrubs can live for more than 50 years, although some hybrids have shorter lifespans.
How Can I Tell If My Hibiscus is Hardy or Tropical?
Tropical hibiscus flowers have a greater color range than hardy hibiscus flowers. These flowers come in shades of orange, yellow, peach, and salmon. Tropical hibiscus also has dark, glossy leaves, while hardy hibiscus has lighter, heart-shaped leaves.
How to Grow and Care for Tropical Hibiscus: Wrapping Up
Tropical hibiscus are beautiful evergreen shrubs that thrive in Zones 9 to 12. These tropical plants can’t survive frost or cold temperatures below 40ºF, so grow them in pots in colder areas. Tropical hibiscus plants need full sun to partial shade and fertile, well-draining soils. Plant them in sheltered areas to protect them from the cold.