Palms for Autumn Planting

Believe it or not, southern Florida is beginning to cool down, at least statistically. Our region has endured a very warm summer; we seem to have had temperatures 3-5 degrees above historical averages for months. However, the day-night mean temperature for mid-October should be 80°, down from 85° during the July-August peak.

 While we are entering the time of year when a lot of palm species don’t take kindly to transplanting, this is an excellent season in which to plant container-grown palms. That’s because their root systems are established and won’t have to go through recovery from being cut. Container-grown palms installed during the autumn are able to expand their root systems over the winter months so that the plants can put on vigorous crown growth when hot weather returns. All that’s necessary is steady watering so that rootballs stay hydrated.

 Richard Lyons’ Nursery has a good variety of palm species available for your autumn planting projects. This week we’ll take a look at some of the species that are available in 1-gal. containers:

 Coccothrinax argentata is one of Florida’s native species. The strong silvery coloration found on the undersides of its leathery leaves gives rise to its common name, the Silver Palm. It grows best in a sunny, well-drained exposure and slowly reaches about 20 ft. Fruits mature from white to purple. It is tolerant of poor soils.

 Coccothrinax crinita, the popular Old Man Palm, is endemic to Cuba. Its trunk is covered in beardlike woolly fibers, and the undersides of its palmate leaves are silvery. In our region, this sun-loving species can reach 25-30 ft. slowly. It requires moderate water and good drainage, but is drought-tolerant once established.

 Dypsis cabadae is a water-loving species that was almost unknown here 35 years ago. Its dark green stems with white rings marking where leaves once were gives this palm a bamboo-like appearance.  It reaches 30-40 ft. at maturity and can be grown in light shade to sun. It is native to islands off the coast of Madagascar.

 Dypsis leptocheilos, commonly called the Teddy Bear Palm because of the rust-colored fuzz (tomentum) on its crownshaft, is a critically-endangered native of Madagascar. This single-stemmed species matures to about 30 ft. and bears prominent leaf scars on its whitish trunk. It prefers sunny exposures and lots of water. It bears very long pinnate leaves, but almost no petiole.

 Hyophorbe lagenicaulis is the Bottle Palm, a critically-endangered native, endemic to Round Island in the Indian Ocean, near Mauritius, where perhaps only 15 are said to remain. However, due to its popularity in tropical and subtropical climates, this palm is plentiful in cultivation worldwide and is perfectly at home in limestone soils, such as those found in South Florida.  It features a swollen gray trunk and small green crownshaft consisting of 4-8 ascending pinnate leaves. It reaches about 10-15 ft. at maturity.

 

Florida Citrus Takes a Licking, But Not From Greening

For a number of years now, Florida citrus has been pummeled by disease. Citrus canker appeared first, only to be supplanted by a newer scourge, citrus greening. Orange production alone cratered from a peak of 244 million 90-lb. boxes in 1997-98 to 68.36 million (or 68.75 million, depending upon the source) in 2016-17. But for the upcoming season, citrus production was predicted to be higher than at any time in the past five years.

Then Hurricane Irma scoured the state.

On October 12 the USDA issued its first citrus crop forecast for the 2017-18 season, estimating a harvest of 54 million boxes of oranges. That would make it the smallest production since the 1946-47 season. Prior to Irma, a respected citrus consultant forecast an orange crop of 75.5 million boxes. But the USDA’s number was viewed skeptically by people in the industry. Larry Black, the general manager of Peace River Packing Co., said that the forecast underestimated the rate of fruit drop caused by the hurricane.

Florida Commissioner of Agriculture Adam Putnam was in agreement. Following release of the USDA forecast, he observed that “Some estimates would say that groves that were impacted by the hurricane will continue to experience significant fruit drop for weeks to come. So it’s just important I think that we continue to recognize that the damage done to Florida agriculture is still unfolding.” Other critics of the government statistics point out that additional influential factors overlooked by the USDA include wind damage to tree branches and limbs and flood damage to the root systems.

The U.S. Congress’s most recent disaster relief package did not include funds for Florida’s farmers; that remedy is still expected. But there’s another form of relief for the citrus industry that makes an accurate crop estimate essential: The lower the projected harvest – say, in the 30-40 million box range – the higher the prices growers can negotiate with juice processors and packinghouses. With that crucial consideration in mind, Florida Citrus Mutual, the trade group for the state’s citrus growers, asked the USDA to delay its October forecast until it can conduct a comprehensive fruit survey. The request was turned down.

No matter how the question of storm-related damage is resolved, the cloud of citrus greening has not dissipated; there is still no known cure for the disease. Accordingly, as it has done for several years, Richard Lyons’ Nursery is advising homeowners against planting citrus in their yards.

Lessons Learned from Irma – Postscript

As a follow-up to last week’s article, Richard Lyons’ Nursery would like to make a couple of additional recommendations in the wake of Hurricane Irma:

As to palms, plant more. As to Ficus benjamina, plant fewer.

Palms appear to have weathered Irma quite well in comparison to broadleaf trees. The explanation in most cases is their architecture. Single-trunked species in particular present a relatively slender profile in the face of strong winds. Even the tall-growing Royal Palm is quite resistant to hurricanes. Longtime observers of tropical weather know that only the strongest hurricanes knock Royal Palms down in any quantity. The key to their success is that they not only bear a small number of leaves, but those leaves snap off in fierce winds, leaving a figurative pencil in the landscape. Similarly, other palm genera which hold a limited number of leaves – such as Veitchia, Chambeyronia, and Satakentia – had a high survival rate versus Irma.

Ficus benjamina, on the other hand, performed miserably. There are lots of ficus species in the world – upwards of 800 – and many are worth having in the landscape of southern Florida, but the widespread use of Ficus benjamina has become quite questionable. It’s an understatement to say that this species comes with a lot of baggage. First, the tree’s very form is an invitation to demolition via wind, even just gusts from a heavy thunderstorm. The crown is not only broad, but extremely dense. Consequently, it doesn’t allow strong breezes to pass through, instead putting up resistance that often yields bad results.

The execrable practice of hatracking, now illegal in many municipalities, certainly reduces canopy in the short run, but fails in the long run because new growth creates an even denser crown. A superior technique, selective pruning, also known as pick-pruning, can succeed in opening up the crown of F. benjamina by removing entire branches, but it is a labor-intensive endeavor. The U.S. Forest Service has gone on record since at least 1993 discouraging the use of this species in residential settings.

Second, the root system of F. benjamina is notoriously aggressive, capable of heaving not only sidewalks, but also foundations and even interior floor finishes such as terrazzo. The limestone substrate in much of Miami-Dade County further exacerbates the problem by confining the root system to a shallow zone. When a specimen of F. benjamina falls, its root system can lift a mass of sod, soil and rocks 12 ft. or more into the air.

Third, the plant’s aerial roots are both a blessing and a curse. They have a purpose: Upon touching the soil they form a new trunk that helps stabilize the tree. But that trait also permits the tree to enlarge to dimensions unsuitable to most home landscapes. When owners cut the roots above ground to control the tree’s spread, they also destabilize it.

There is no denying the allure of F. benjamina as an ornamental plant; its use has long distinguished the roadways of Coral Gables. But even the City Beautiful recognized the maintenance demands and risks associated with the species. In recent years, it has been replacing F. benjamina with Live Oak, a species more amenable to sculptural pruning, less demanding of maintenance, and more capable of withstanding tropical storms.

 

Lessons Learned from Irma

Just about everyone in southeastern Florida was able to breathe a sigh of relief after Hurricane Irma left the area. Its 11th-hour course change allowed us to escape a devastating direct hit, and our homes were largely left intact. However, many of our trees suffered greatly, even though officially they were battered by ‘only’ tropical storm-force winds.

Tropical storms are not all alike; each one provides bits of information that help us better understand these capricious natural systems. This brief article addresses some of the lessons learned from our experience with Irma.

There appear to be at least three reasons why the landscape of southeastern Florida took such a beating from the storm:

(1) Duration – We were subjected to strong winds for a long time following their start on Saturday, September 9. Those of us who ventured out just before sunset on September 10 still experienced occasional strong gusts. Clearly wind strength is not the only variable influencing the capacity of a tree to survive; even winds of sub-hurricane strength can cause great damage if they last long enough.

(2) Pruning Practices – Lots of trees blew over or cracked up because they had not been pruned to deal with tropical storms. Good pruning opens up a canopy so that it allows wind to flow through it rather than to create resistance by acting as a sail. The most successful pruning is done over a three-year period. This is especially important if the homeowner wishes to keeping fruit trees producing every year; severe pruning performed all at once can halt fruit production for a season.

(3) Planting Practices – All over our region there are examples of trees that were planted improperly. The evidence is the exposed rootball – remarkably small compared to the size of the tree. (In one egregious instance, an upturned tree in the median on U.S. 1 was seen still wrapped by the sides of its container!) Some experts, including those on governmental sites, have been suggesting that a planting hole need only be large enough to accommodate a plant’s rootball. Richard Lyons’ Nursery respectfully disagrees, particularly with regard to installation in the limestone substrate that is so common in our area. For proper root development, a planting hole approximately 5 ft. X 5 ft. should be excavated for planting a new tree. Alternatively, good stability in high winds can be provided by digging an X-shaped trench so that roots can extend a good distance in each direction.

Please keep in mind that the planting hole need not be improved with rich potting soil; that will only serve to confine the tree’s roots to the better mix. Instead, you should backfill the hole with the poor soil and the now-crushed rock that was excavated. That will cause the tree to root out in all directions, making it more stable as it grows up. Water generously to settle the material and eliminate air pockets. Finally, apply mulch over an area that extends further than the rootball. However, in order to discourage insects from invading the plant, do not pile mulch against the stem. Leave an area open 6-8 in. around the stem so that air can circulate.

Geiger, Audubon, and a Special Tree

In 1832, famed avian artist John James Audubon (born Jean Rabin), was visiting a friend in Key West when he gazed into a neighbor’s yard and saw a beautiful flowering tree, which we know as Cordia sebestena. So impressed was he by the tree that his later engraving of white-crowned pigeons shows the birds perched on a Cordia branch.

The neighbor of Audubon’s host was Captain John H. Geiger, Key West’s first harbor pilot and an avid plantsman. The Cordia in his yard was known locally as the Geiger Tree, and eventually several other species in the genus came to be accorded that common name. (In the late 1950s Captain Geiger’s house was about to be torn down in favor of a gas station when the Mitchell Wolfson Family Foundation donated funds for its restoration, the first to be undertaken in Key West. Fittingly, in 1960 the property at 205 Whitehead St. was opened to the public as the Audubon House Museum & Tropical Gardens.)

The Orange Geiger Tree grows at a moderate rate to about 25 ft. in height. It produces large, dark green leaves with a sandpapery texture, and it bears clusters of 2-in. wide brilliant to dark orange funnel-shaped flowers for much of the year. There has been a long-simmering controversy over whether C. sebestena is a Florida native. The species occurs naturally over a large range from the Bahamas through the Caribbean and into northern South America. It seems likely that it was introduced into Key West from Cuba.

But, native or not, the Orange Geiger has proven perfectly amenable to the poor, highly-alkaline soils which are anathema to many other plant species. In addition, it is famously tolerant of drought and salt. For best flowering, it should be grown in full sun.

The White Geiger Tree, C. boissieri, is native from South Texas into Central Mexico. Known also as the Texas Wild Olive, the species matures to 16-23 ft. in height. Its funnel-shaped white flowers are somewhat smaller than those of C. sebestena and appear pretty much year-round. C. boissieri functions as a good subtroical approximation of the Flowering Dogwood. Leaves are silvery-green in color and possess a fuzzy texture. The White Geiger is highly drought-tolerant and can withstand temperatures at least down into the low 20s. Jellies can be made from the fruit of the tree, and its leaves are said to be used in folk remedies to treat pulmonary problems and rheumatism.

The Yellow Geiger Tree, C. lutea, occurs natively in Peru and Ecuador, including the Galápagos Islands. Like C. boissieri, it matures to a height somewhere above 20 ft. It produces bright yellow, funnel-shaped, mildly fragrant flowers throughout the year, but particularly in late spring to early summer. As with the other Cordia species featured here, the Yellow Geiger is quite tolerant of drought and poor soils. In southern Florida it performs well as both a container-grown or inground tree or shrub.

The Orange, White and Yellow Geigers are available at Richard Lyons’ Nursery in various size containers.