Bloom Period and Seasonal Color
Blooms from spring to fall and is a broadleaved evergreen
Mature Height x Spread
8 to 15 feet x 5 to 10 feet, although can be larger in tropical areas such as Hawaii
Tropical hibiscus is an evergreen shrub that is only hardy to USDA zone 10-11. This means it’s limited to growing outdoors in the United States to subtropical areas of California, Texas, Arizona and Florida as well as Hawaii. It’s often grown as a foundation plant or mixed with other subtropical plants and flowers in the landscape. The large, disc-shaped flowers come in a myriad of colors and can be single or double. It blooms from spring to fall.
For most of the U.S. tropical hibiscus is grown as a potted plant. Even in areas where it can survive the winter in the ground, it still is grown in containers for ease of cultivation and ability to move the plant around in the yard. Tropical hibiscus doesn’t grow well with temperatures below 45F, so it’s moved outdoors in late spring in cool areas, and indoors with the first hint of cold weather in fall.
When, Where and How to Plant
Plant tropical hibiscus in the ground or containers from spring to fall. Tropical hibiscus needs a good supply of water to grow well, so planting before a rainy season is best in subtropical areas. Purchase tropical hibiscus plants from a garden center. If planting in the ground, choose a well-drained location that gets full sun for best flowering. In hot areas, tropical hibiscus can stand some afternoon shade, especially if grown on sandy soils. Amend the soil with compost if it’s sandy or has poor fertility. Space plants outdoors 4 to 6 feet apart. Tropical hibiscus can also be grown as an informal hedge. Space plants closer if growing as a hedge.
Plant tropical hibiscus in containers one size larger than the root ball. Use a potting soil mix that’s high in organic matter and is well drained.
Tropical hibiscus grows best with a constant supply of water. Apply 1- to 2-inches of water a week and mulch plants for best flowering. In containers, keep the soil evenly moist with drip irrigation or regular hand watering. Empty the water drainage trays under the pots regularly to remove standing water. Standing water can make the container soil too soggy and cause root rot. Fertilize tropical hibiscus monthly from spring through summer with a balanced fertilizer for tropical plants..
Tropical hibiscus looks and flowers best if allowed to grow into its natural shape. Hibiscus forms flowers on new growth, so pruning stimulates more branches and more flowers to form. Prune tropical hibiscus plants that are getting out of control, or need to be stimulated to produce more branches, in late fall in warm areas. In areas where the plants are marginally hardy, prune in spring. When growing in containers, prune in early fall before bringing indoors for the winter. Tropical hibiscus can tolerate severe pruning in spring and will grow back and flower later in summer. Otherwise, prune to reduce crowded branches, open up the shrub to more light and shape the plant. Remove dead, diseased or broken branches anytime.
When overwintering tropical hibiscus indoors in cold winter areas, expect to get some yellowing and dropping of the leaves, even if you place the shrub in a south-facing winter. This is natural due to the low light levels in winter. Place the plant away from cold drafts in a warm room. You can prevent leaf drop by growing the plant under grow lights. Bring the plant indoors at first sign of cold weather in fall. Isolate the plant indoors at first to check for hitchhiking insects such as aphids, white flies, spider mites and mealybugs. Spray with insecticidal soap to kill these pests before they spread to other houseplants. Don’t expect much flowering in winter unless you’re growing plants under lights. Keep the soil on the dry side all winter and don’t fertilizer. New growth will start in late winter as the days get longer. Increase watering and fertilizing as new growth forms.
Companion Planting and Design
Plant tropical hibiscus shrubs around the home, grouped with other subtropical shrubs in the landscape or as a specimen in a container or in the yard. Tropical hibiscus look good paired with cordyline, plumbago, and bougainvillea. Even potted plants placed outdoors in summer look nice with canna lilies and fountain grass growing near them. Place tropical hibiscus under vines such as jasmine, mandevilla and passion flower. These colorful hibiscus shrub providing a good anchoring plant growing under these vines.
There are many colorful tropical hibiscus varieties, often with 8-inch wide flowers, available in single and double flowers. Try the Shades of Summer Series and Tropical Escape series for a broad range of color choices. ‘Golden Gate’ has ruffled golden petals with a pink and red eye. ‘Love Story’ is an award winning double red. ‘Bright Hope’ has yellow, pink and red color petals all on one flower.