The Queen of the Tropics: Exotic Hibiscus
November 8, 2021
By Karen Maxwell, Horticultural Specialist
The McGregor Boulevard landscape that borders the Edison and Ford Winter Estates is well known for its historic rows of royal palms. In the late 1920s, that landscape was far more colorful as it included hibiscus shrubs which were planted in between the palms as part of Mina Edison’s contribution to her roadway and park beautification efforts. While her husband, Thomas, procured plants primarily for his rubber research and tropical tree collection, Mina Edison called upon her extensive travels and knowledge of trends to surround their Fort Myers home with beauty and style.
In 1901, when the Edisons returned to Fort Myers and Mina began creating her tropical gardens in earnest along the banks of the Caloosahatchee River, she received the input of nationally acclaimed landscape architects John Nolan, Hale Walker and Ellen Biddle Shipman. As the gardens evolved, she implemented the suggestions of these designers with the guidance of local growers that Thomas Edison insisted be used, but she imparted her own experience, good sense, and horticulture education to create her vision of a modern tropical oasis.
The Arts and Crafts period in the U.S. (1890s-1920s) imprinted its style on American gardens as well as architecture and pottery just as women were assuming the primary care of home gardens, though in the upper class, this was often done behind hedges or with hired help. Mina Miller Edison, an astute horticulturist in her own right, spent most of her summers at the Miller Home in Chautauqua, NY which was surrounded by epicenters of the Arts and Crafts movement and she sought to include the design in her gardens in Fort Myers.
One garden trend in Arts and Crafts gardens was the inclusion of standards – shrubs that were grown and pruned to remove lower branches, thereby creating a small tree. Heliotrope standards, one of the most popular, were included by Mina in her Fort Myers garden as she loved the vanilla scented, lavender plants. Unfortunately, the harsh wet and humid summers of Southwest Florida doomed the future of her heliotropes, along with many other initial perennials, and Mina sought alternatives, better suited to the local climate.
As early as 1908, according to the meticulous record keeping of Edison’s caretaker Ewald Stulpner, the Fringed Hibiscus, also called Chinese Lantern (Hibiscus schizopetalus*) was purchased for the grounds. This species hibiscus, native to East Africa, is not quite as well-known as its tropical cousin – Chinese Hibiscus (Hibiscus rosa-sinensis*) but is a wonderful specimen for South Florida gardens that can provide lots of space for the long arching stems full of small and lighter green leaves, often variegated that produce deeply lobed and fringed flowers which hang down like a chandelier as opposed to the Chinese hibiscus flowers which open face up. Also, unlike the Chinese hibiscus, this hibiscus does not like to be pruned as flowers appear on the previous year’s wood. This is a thirsty hibiscus and will perform well with regilar, deep irrigation, no additional fertilization, and a sparse pruning once every 3-5 years.
At the suggestion of family friend and local grower, James E. Hendry, Jr., who had opened The Everglades Nursery Company also on McGregor Boulevard in Fort Myers, Mina Edison replaced her failed heliotrope standards with Chinese Hibiscus standards (Hibiscus rosa-sinensis*) which is the popular hibiscus that most people associate with Florida and Hawaii and the most hybridized of the hibiscus family. Credited with developing many hybrids of bougainvillea, James E. Hendry, Jr. created hundreds of these hybrids and he often named them after friends and family – including a variety named “Mrs. Thomas A. Edison” which the company catalog described as “Yellow with a peach center in the morning, fading to clear yellow in the afternoon.” (Note: We do not have this hibiscus presently in our gardens and would love to receive a cutting if one of our readers should have one.)
Mina purchased many hibiscus hybrids from Hendry, and they worked together to add these tropical flowering shrubs to her street beautification and park improvements around Fort Myers. Today, the James E. Hendry Chapter of the American Hibiscus Society based in Fort Myers is nearly 70 years old. This group was so important to Mina, that even though her husband was gravely ill in 1931, she made the time to meet with the Society. The club will be at the Edison Ford fall Garden Festival, November 20-21; for hibiscus fanciers, this is a wonderful chance to obtain rare and unusual plants and get expert advice on the care and growing of Hibiscus sinensis-rosa.
Today, Mina’s hibiscus standards Double Peach and Double Red greet visitors as they enter the grounds on the river side of the property. White Wings, a desirable white cultivar, is in the adjacent Croton Garden.
Hibiscus is part of the enormous Malvaceae or Hibiscus family of which the Edisons grew many species, including the Chinese Hibiscus (Hibiscus rosa-sinensis*), Fringed Hibiscus (Hibiscus schizopetalus*), Turks Cap Hibiscus (Malvaviscus arboreus*), and Okra (Hibiscus esculentus*). This family of plants also includes Cacao (source of cocoa beans), Cotton, Dombeya* and Ceiba (the Kapok*).
Florida is also home to several native species. The Scarlet Hibiscus (Hibiscus coccineus), which like all hibiscus species is not salt tolerant. A great hummingbird and butterfly attractant, this is an excellent addition to a garden that can sustain a sunny and constantly damp or bog-like environment, though it is dormant in the winter.
The ideal site for hibiscus is where they can receive up to 12 hours of sunlight a day and will happily tolerate some dappled shade in the late afternoon. All hibiscus discussed in this article are shallow-rooted plants that require good water, but they won’t tolerate soggy conditions, except for the Florida native. Stake newly planted hibiscus plants, especially standards to compensate for the shallow root structure until they are well established. Adding good compost to our sandy soils will provide the nitrogen needed for good growth and to provide the slightly acidic soils that yield optimum performance and a thick layer of
mulch will protect the temperature of the soil on those shallow roots and help retain moisture. This is especially true if one is planting close to a concrete foundation or walkway where lime leaches into the soil and raises the pH above the preferred level of 6.5 or so. As anyone who has grown hibiscus will tell you, they are easy to grow, but they do have some issues – some we can control and others we cannot.
Our southwest soils tend to be low on potassium (K) and too high on phosphorous (P) so providing a regular feeding of a slow-release granular product, such as Sure-Gro (the same product we use and recommend for palm trees) has the best formula of 8-2-12, which includes ample nitrogen for excellent growth. The variegated variety of the Fringed Hibiscus produces an attractive white and light green foliage. For a mass of beautiful foliage, Tricolor Variegated Hibiscus sometimes sold as Red Hot (Hibiscus rosa-sinensis cooperi*) prunes well and offers a stunning dark green with shades of hot pink foliage in addition to its singular red flowers.
Keep your standard Chinese Hibiscus (Hibiscus rosa sinensis*) pinched to maintain a compact plant with good form and shape but remember not to prune or pinch the Fringed hibiscus (Hibiscus schizopetalus*) as discussed earlier. When pruning is in order, try to avoid doing so in mid-winter. Pruning encourages new growth, and should a winter frost occur, the tender new growth will be injured and possibly cause more severe damage to your plant(s).
A possible hybrid of the Hawaiian white Hibiscus (Hibiscus arnottianus) and the Fringed Hibiscus, is the Weeping Hibiscus, or Dainty Pink Hibiscus (Hibiscus rosa-sinensis) and the white variety known as Dainty White (both also are called La France*) which, is believed to be a normal mutation of the Dainty Pink, both of which grow throughout our gardens, including the Moonlight Garden. As the name suggests, this cultivar sports weeping stems and will grow to nearly 10 feet. Covered with 3” blooms, growers will enjoy the multitude of butterflies, hummingbirds and pollinators that cannot resist it. Hybridized or imported in the late 1950s, the Dainty Pink is credited to Norman Reasoner and L.K. Thompson. Reasoner owned and operated Reasoner’s Tropical Nursery outside of Bradenton and consulted Mina and Thomas Edison in the late 1920s.
All hibiscus are prone to a variety of insects including aphids, scale, mealybugs, etc. Should you discover these pests, apply a wash of horticultural soap or oil two times a week until they are extinguished. Severe cases of pests may require a drench, but keep in mind that products with imidacloprid, a neonicotinoid will harm pollinators. When in doubt, please don’t hesitate to contact a staff member of the Edison Ford Horticulture Department.
Despite providing the best care to hibiscus plants, there are times that yellowing or leaf drop is unavoidable. Hibiscus are known for not appreciating rapid changes in their environment, including temperature and humidity, and this is often the case when acclimatized or potted plants are suddenly moved inside to protect them from a frost, or extended periods of drought. Keep in mind that none of the hibiscus are salt tolerant and whenever possible, avoid using water that goes through a water softener system which employs salt. If all other conditions are met, hibiscus is actually a pretty rugged tropical plant, and it will come back when the temperature and humidity are more to their liking. Today, the number 1 selling hibiscus is Fiesta (Hibiscus rosa-sinensis) and is often available in our Garden Shoppe along with most of the varieties discussed.
In this article, we hope to impart the importance of the hibiscus to our Fort Myers history; it is impossible to cover all of the varieties, types and information about growing this beautiful plant here, but feel free to explore further the American Hibiscus Society and our local, James E. Hendry Chapter.
*Indicates plants in the Edison and Ford Winter Estates gardens.