Tropical woody ornamentals: for southern Florida gardeners

Flower & Garden Magazine, Dec-Jan, 1994 by Cathy Ryan

Many aspects of life in southern Florida distinguish it from the rest of the country -- most obviously the climate. Nighttime temperatures rarely dip below the 40s in the winter and lows of 80 degrees are common in the summer. Daytime temperatures range from the mid-70s to the mid-90s most of the year.

The subtropical to almost tropical conditions of Dade and Monroe counties are not conducive to growing the temperate plants with which many who relocate here are familiar. When I moved to south Florida more than six years ago, I also experienced this gardener's culture shock. I found very few plants that I recognized other than some foliage plants I knew from their use in northern shopping malls and offices.

During my first year here there were several plant species that caught my eye because of their colorful show. Among them were trees such as Delonix regia and several Tabebuia species as well as shrubs like Brunfelsia and Duranta erecta and a vine, Strongylodon macrobotrys.

Also known as royal poinciana in our area, Delonix regia is a large, fast-growing tree that needs a lot of space to develop properly. This tree is valuable for the shade provided during the hot summer months. The royal poinciana is a member of the Leguminosae or pea family and is native to Madagascar, where it is in danger of becoming extinct. It has been estimated that there are more royal poincianas outside of Madagascar than on the island itself. This species has several common names: flamboyant in Madagascar, peacock flower in India and royal poinciana in Hawaii and south Florida.

The trunk of this tree is slightly buttressed at the base and has a crown that spreads 1-1/2 to two times the tree's height. The leaves are very large and have 20 to 40 pairs of leaflets. For a short time during the dry season, the tree loses its leaves. Flowers appear in late spring to early summer on the new season's growth. There are several colors: orange, yellow and various shades of red, with scarlet being the most popular. The flowers are similar to those of honey locust and the Kentucky coffee tree, related trees of temperate climates. For good bloom, the royal poinciana likes to be kept on the dry side in winter and is best grown from seed.

Trumpet trees (Tabebuia) are native to most areas of the New World tropics. They come in several colors including red, lavender, pink, purple and yellow. Tabebuias bloom throughout most of the year. One of the species frequently planted is the spring-flowering Tabebuia argentea (also known as Tabebuia caraiba), which has bright yellow flowers in clusters at the branch tips. The leaves have contrasting silvery undersides. This tree does well throughout central and south Florida due to the mild, dry winter climate that triggers spring bloom.

T. rosea is a popular reddish-pink species that does well in wet or dry areas. Trumpet tree is an appropriate name because of the bell shape of the flowers. Many of the pink-flowering species not only survived the winds but also burst into unusually heavy bloom in the Miami area after the devastating passage of Hurricane Andrew in August 1992. The flowers were cheery spots of color amidst the surrounding destruction.

If you are looking for shrubs to add to your landscape design, Brunfelsia and Duranta are good reliable choices. Brunfelsia has blue-purple flowers that fade to white over a period of days, hence the common name of yesterday-today-and-tomorrow. The bloom period lasts from December to April. This plant can be used as a hedge or as a specimen planting. It has rather large leaves, which in its native area of northwestern South America are used for medicinal purposes.

Native to south Florida is Duranta erecta (formerly classified as D. repens), another blue-flowered shrub that has at least one flower on the bush every day of the year. The flowers are followed by small golden fruits that give the shrub the common names of golden dewdrop or pigeon berry. There is also a white-flowered form that is still referred to in the nursery trade as D. repens 'Alba.' Except for some minor pruning, neither requires extensive care.

For gardeners in areas north of southern Florida, Brunfelsia and Duranta can be grown in greenhouses and conservatories, provided that they are given a lot of light.

When I first saw Strongylodon macrobotrys (jade vine) in bloom, I thought I had been transported to the Starship Enterprise. The flowers look like jade-colored lobster claws. They hang down below the foliage in long, pendulous racemes. The plant requires support from a tree or an arbor. This beautiful vine is susceptible to nematodes, the microscopic soil pests that invade the plant's roots. Mulching helps protect against nematodes. The jade vine, native to the Philippines, does well in sunny protected locations.

RELATED ARTICLE: SOURCES

Bloomin' Good Flowering Tree Nursery

20905 S.W. 240th St., Dept. FG Homestead, FL 33031

(free price list; lists Brunfelsia, Delonix regia, Duranta, Strongylodon macrobotrys)