While all hibiscus are created equal, we all have our favorite flower colors, sizes, and shapes. The tropical hibiscus is one of the most popular shrubs in our area due to its variety and color. From low, spreading types to upright forms, hibiscus can be used all over your landscape. Beyond the flower color, there is another dimension – a dimension of foliage color.
Tropical hibiscus as a group are evergreens normally decked out with green leaves. These rich green leaves are a necessary, but often secondary, ornamental backdrop to the spectacular flowers. However, once you have seen non-green hibiscus leaves, you may want to add a little “vegetation variegation variation” to your landscape. One very popular hibiscus cultivar that has both beautiful flowers and colorful foliage is called ‘Red Hot’. As a description, ‘Red Hot’ has red flowers and pinkish red, maroon, green and cream-colored variegated foliage. As a stand-alone, the foliage is ornamental enough, and the red flowers are simply the icing on the cake! Another cultivar with a different approach is called ‘Snow Queen’ which has variegated white, cream, and green coloration. Again, the red flower on this type punctuates this eye-popping variegated apparition.
No matter what hibiscus you select, they can used in the landscape as hedges, screens, foundation plants or as a background for other plants. Informal, unsheared hedges do better than sheared plants. Hibiscus can also be trained as “standards” or tree-forms that make excellent specimen plants. Some hibiscus do well on their own roots, while other newer types are grafted. Although hibiscus can be killed to the ground at twenty-eight to thirty degrees F, well-established plants will resprout in the spring. Fences, buildings, screens, or trees can act as microclimates and provide protection from cold northern winds. Keep in mind also that these plants are not tolerant to salt spray or salty water. When selecting a site to plant hibiscus, consider that these evergreen plants appreciate somewhat acidic, well-drained soil in a full-sun to part-shade exposure. For established plants, use a granular fertilizer suitable for azaleas– perhaps once in May and once in October – applied as per label directions. Too high a soil pH may cause micronutrient deficiencies. Micronutrients may be applied as foliar sprays during the summer being careful as these materials will stain concrete and stonework.
Pruning is always a big question with hibiscus growers. General pruning is best conducted in March after the danger of frost, and just before new growth starts. Light maintenance pruning of diseased, dead wood or crossing branches can be accomplished at any time of year. It is important to keep in mind that hibiscus blooms develop on new growth. If heavy pruning occurs during the active growing season, blooming will be delayed.
While hibiscus have a few pests, bud drop is often one of the more perplexing problems. Bud drop can, by nature, be more common in some varieties. Thrips, midges and caterpillars can also contribute to this condition. Physiological or environmental factors may also affect buds and can be attributed to nutritional problems, too much fertilizer, poor drainage, drought, or salt spray.
Variegated hibiscus are generally available at most garden centers. Otherwise, check on-line for mail order nurseries. Overall, hibiscus are a worthwhile landscape plant that should be in your garden plan. For something different, use these hibiscus known for their colorful leaves that just add to the ornamental quality of this already popular evergreen shrub! For more information on hibiscus or other flowering shrubs, you can also call the Master Gardener Volunteer Helpdesk on Mondays, Wednesdays, and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Ralph E. Mitchell is the Director/Horticulture Agent for UF/IFAS Extension – Charlotte County. He can be reached at 941-764-4344 or ralph.mitchell@charlottecountyfl.gov.
Resources:
Ingram, D.L. & Rabinowitz, L. (2004), Hibiscus in Florida, The University of Florida Cooperative Extension Service, IFAS.
Dave’s Garden (2015) Hibiscus rosa-sinensis ‘Snow Queen’. https://davesgarden.com/guides/pf/showimage/391859/
Dave’s Garden (2022) Hibiscus rosa-sinensis Tropical Hibiscus ‘Red Hot’. https://davesgarden.com/guides/pf/go/46827/
The Florida-Friendly Landscaping™ Guide to Plant Selection & Landscape Design (2010) The University of Florida Extension Services, IFAS.
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