Indian River County Extension Service
                                     1028 20th Pl, Suite D
                                     Vero Beach, FL 32960

                                                                                                                                           12 June 2002

FOR RELEASE: 16 June 2002

Daniel F. Culbert, County Extension Director


Many fathers would like nothing better for Fatherís Day than to lie in a hammock under the shade of a tropical tree and enjoy a good book or a favorite beverage. In our area, one of the tropical trees that might provide a suitable canopy is the Royal Poinciana. At this time of year, the spreading branches with fern-like foliage have erupted with their brilliant orange-red flowers.

This large tropical tree is appearing with more frequency in the Indian River area. Todayís column will talk about its use in our Florida Yards, and offer a challenge to readers to nominate specimens that have been spotted in local landscapes. Information for todayís column is based on a Southern Tree Fact sheet produced by University of Florida Extension Specialist Ed Gilman.

The Royal Poinciana is claimed to be among the most beautiful trees in the world. It was named in honor of after the first French Governor of Saint-Cristophe (now called St. Kitts), Monsieur de Poincy. Other commonly used names for this beauty are the Flamboyant or Flame tree, and one look at its brilliant summer appearance ought to convince anyone where this name comes from. Botanically, it is called Delonix regia , which refers to the long clawed petals of this "royal" tree.

Even out of its flowering season, this many-branched, broad, spreading, flat crowned deciduous tree is adapted for frost free Florida Yards. But its brilliant display of red-orange blooms fires up tropical tree tops from May through July. There is nothing like a Royal Poinciana (or better yet, a group of them) in full bloom.

Individual flowers may measure up to four inches across. There are five spoon shaped petals in each flower, with one petal of each flower marked with lighter white and yellow stripes. Flower color varies greatly, and can range from deep scarlet to brick orange - there is even a yellow flowered form (var. flavida) found in the Caribbean countries. The flowers grow from the ends of each branch, and the show on a particular tree can last for more than a month.

Poinciana flowers give rise to large bean-pod fruit. How big can these bean pods get? The Poinciana is a member of the Legume family, and one look at its fruit will tell you: Eighteen-inch-long and two or more inches wide, the dark brown Poinciana seed pods hang on the tree throughout the winter, then fall on the ground in spring. These pods look like the old fashioned razor strops that dad might see in the barber shop. The woody pods falling onto the ground may be a litter nuisance; this is one of the down sides of this tree as a landscape plant. While the seed of some other legume trees may be toxic, one researcher has confirmed that the seeds are not poisonous, and were in fact a good source of animal feed in his African experiment.

Inside the pods are seeds that can be used to grow more Poincianas. Theses hard smooth seed are an inch long and 1/4 inch wide, and are gray brown in color. There is a trick to getting the seed to germinate. Because the seed covering is very had, it will take a long time for the seed to absorb moisture to get them growing. One grower reports good success with a 4 minute dip in boiling water, followed by an overnight soak in warm water. A method that I have used is to carefully look at the seed to locate the embryo end - look for a small spot at the tip - the seed scar. Using a pair of pliers, carefully break off the smallest possible piece of the OPPOSITE end. This will allow the seeds to absorb moisture and start germination. Plant and grow as you would any other seed this size.

Poincianas in Florida Yards

The fine, soft, delicate leaflets give dappled shade during the remainder of the growing season, making Royal Poinciana a favorite shade tree or freestanding specimen in large, open areas. Leaves alternate on the stem, and one leaf may measure up to 18 long by 6 inches wide. For the botanists among us, the Poinciana is bipinnately compound, which means the leaf is divided, twice, into several hundred small sub-leaflets no longer than one-half-inch long. This is what gives the Flamboyant tree itsís ferny foliage appearance.

UF Horticulture professor Dr. Bijan Dehgan reports that the fallen leaves are suspected of being detrimental to turfgrass; they may produce a sort of natural herbicide. In my experience, large Poincianas provide enough shade that turf grass would suffer from a lack of light, a common situation with many other heavily foliated trees.

The Royal Poinciana is fast growing and can get quite large. They have a distinctive shaped canopy that is broader than tall, and will grow to about 40 feet high and 60 feet wide. Trunks can become as large as 50 inches or more in diameter. Give it plenty of room, about 10 feet from away from sidewalks and driveways that may be lifted by the roots or where fallen branches and pods may present problems. It will grow fast, five feet per year, and provide instant shade. Locally, people have planted Poinciana trees that in 6 or 7 years have reached 30 feet tall, and have begun to bloom at about that age.

Another issue to consider is the cold hardiness of the Royal Poinciana. There are a few references that say they can grow in USDA Hardiness Zone 9b, while others say Zone 10. There is local debate as to which zone coastal Indian River County is in, as we have had few winters that have produced sustained temperatures below 25 degrees Fahrenheit. My advice is, go ahead and try a Poinciana if you have the room, can tolerate the cleanup and are willing to remove a frozen specimen if Jack Frost visits our area.

Besides lots of room, the Royal Poinciana will do best when planted in full sun. Tolerant of a wide variety of soils and conditions, Royal Poinciana needs to be well-watered until established, but after that, only during droughts. It is used in tropical areas as a reclamation plant, successfully growing in urban areas where air pollution, poor drainage, compacted soil, and/or drought are the site conditions.

Another downside of the Poinciana that occurs with other fast growing trees is that the limbs are susceptible to breakage. Look for problems to occur either at the crotch due to poor collar formation, or randomly on the limbs because the wood itself is weak and tends to break. Early pruning encourages branches that are well attached to the trunk - this will help compensate for the weak wood. To develop strength, prune major limbs to keep them no larger than half the diameter of the trunk. The branches droop as the tree grows, and will require pruning for cars or if sidewalks are beneath the canopy. Train the tree so the major limbs are located 8 to12 feet from the ground to allow for adequate clearance.

Because seed are so hard to get started in nature, there is limited invasive potential with this tree. It is generally spread by planting, not by wind or wildlife. There are no significant pests or diseases of major concern, although some caterpillars can eat the foliage. There is a root fungus which can kill a weakened or declining tree, or one that has been damaged by too much girdling from nylon string weed whackers.


Whereís Our Prettiest Poinciana

A few years ago, I was involved with a group of volunteers that started a Royal Poinciana festival in West Palm Beach, patterned after another event in Miami. They planned an event, sold seedlings, and had a contest to recognize the prettiest Poinciana in town. They also helped conduct a successful campaign to have a Royal Poinciana printed on a US Postage stamp in 1999.

While I donít think our community has enough of these Flamboyant trees to justify such an event, Iíd be willing to hear from readers who have seen especially attractive specimens that are worthy of some informal recognition. If you have seen an especially attractive Poinciana growing in our area, please let me know where it is located, and give me the name of the property owner if you know it. Pictures can be submitted too. Iíll take a look at them and offer a list for those that are interested in seeking these beautiful tropical trees.

The Southern Tree fact sheet on the Royal Poinciana is available on the Internet at . If you need additional information on Royal Poincianas, visit our Master Gardeners, or call or stop by our office. For those with other questions about Florida Yards, our office holds Master Gardener Clinic hours at the Extension office (1028 20th Place, Suite D, Vero Beach) every weekday morning and most afternoons, Wednesday mornings at the newly refurbished North County Library in Sebastian, and the first Saturday of the month at the Environmental Learning Center. Our phone number is 770-5030, and you can e-mail us at . Have a Flamboyant Fatherís Day!