Hibiscus In Florida
SEMINOLE COUNTY URBAN HORTICULTURIST
The Chinese Hibiscus is one of the most popular and widely planted shrubs of the tropics. This plant is believed to be native to China and most of the varieties grown in Florida are probably hybrids. Most hibiscus varieties have one-day flowers, which typically open early in the morning and wilt late that afternoon. Flowers of a few varieties remain open for two days. Most Hibiscus are odorless, but a few varieties are slightly fragrant. Hibiscus flowers can be red, orange, yellow, white, lavender and brown in color with a broad range of color combinations, color shades and flower forms.
Climate: The use of hibiscus as an evergreen shrub in Florida is limited to the southern half of the peninsula. The limiting factor for growing hibiscus in central and north Florida is low temperatures. Plants will be killed to the ground by temperatures near the freezing point (28-30 degrees F). Established plants may come out in the spring and bloom on new growth that summer. The minimum amount of sun required by hibiscus generally is considered to be half a day of direct sunlight.
Soils: Hibiscus will grow in a wide range of well-drained soils if proper fertilization is provided. A soil pH of 5.5 to 6.5 is preferred. Hibiscus grown on alkaline soils may suffer from micronutrient deficiencies, especially iron and manganese.
Fertilization: Three to four applications of fertilizer per year are recommended for hibiscus. The amount of fertilizer per application depends on frequency of fertilization and size of the plants. Use one-quart of a cup of 10-5-10 or similar fertilizer for small plants and up to one-half cup for mature plants in each application. To promote growth and increase blooming, fertilize once a month. Water plants immediately after applying the fertilizer to prevent fertilizer burn.
Planting and Transplanting: Container-grown hibiscus can be planted any time during the year, but transplanting in the yard is best done during the cooler months. Hibiscus should be planted at the same depth as they were in the container or field. Plants should be watered thoroughly immediately after planting and frequently enough to prevent wilting until they are well established. The use of organic mulch will conserve water, reduce weed problems and help control nematodes.
Irrigation: Hibiscus requires well-drained soils and do not tolerate wet soils but will require regular irrigation during periods of drought. Hibiscus should be watered heavily about once a week during dry periods, applying enough water to wet the soil to a depth of 12 to 18 inches.
Pruning: Spring is the best time of the year to prune Hibiscus. Pruning late in the fall or in the winter should be avoided. Light maintenance pruning may be done any time of the year to remove diseased or dead wood, rubbing branches and weak or droopy growth. Freeze damaged plants should not be pruned until new growth appears, but dead leaves can be removed anytime. Hibiscus blooms are produced on new growth, therefore do not prune during the active growing season.
Propagation: Hibiscus can be propagated from seed, cuttings, by air layering, budding or grafting. Seedlings are quite variable and are never identical to the parents. Grafting or budding are used primarily to propagate varieties that are highly susceptible to nematodes or do not produce strong plants on their own roots. Cuttings are used commercially to propagate hibiscus. Cuttings are taken from new growth in the spring and summer and placed in a well-drained medium, usually containing equal volumes of fibrous peat and coarse builder's sand. A rooting hormone may be applied to the cuttings to promote root formation.
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