There’s a good reason the sabal palm is Florida’s state tree. It takes on a hurricane like a champ and lives to tell the tale.
After Hurricane Andrew, the only plants left standing in south Miami-Dade County were the palms, said Palm Beach landscape architect Mario Nievera.
“Almost everything else was devastated,” he said.
Andrew has become everybody’s yardstick to measure whether a tree can withstand hurricane winds.
Gene Joyner, an urban horticulturist with the Palm Beach County Cooperative Extension Service, said the trees that made it through Andrew’s 155-mile-per-hour winds were natives. Palms especially have adapted to the tropical conditions that breed hurricanes. They bend in the wind, a coping mechanism that helps keep their sturdy trunks intact.
But non-native trees do not have that ability to tough it out.
“If you bring them in, you can expect damage,” Joyner said. A case in point: “Most Australian pines were horizontal after Andrew.”
In high winds, the limbs of brittle trees such as the Australian pine (Casuarina spp.), the jacaranda (Jacaranda acutifolia) or the eucalyptus (Eucalyptus spp.) will snap off like matchsticks.
“You get a branch 20 feet long, it’s going to do a lot of damage,” Joyner said.
Other bad choices are the earleaf acacia (Acacia auriculiformis), the silk oak (Grevillea robusta) and the Norfolk Island pine (Araucaria heterophylla). “They are all nightmares in hurricanes, and, if you have any left, you should get rid of them,” said West Palm Beach landscape architect John Lang.
Even native trees, however, will not bear the brunt of strong winds without proper care. Arborists say regular pruning is the most important factor in protecting trees and, therefore, your property from wind-damage.
Wind-resistant trees have developed strong root systems, not easy given South Florida’s high water table. Trees don’t so much dig in here as they spread. And shallow rooters are more vulnerable to strong winds.
Some long-lived native trees, such as the live oak (Quercus virginiana) and slash pine (Pinus elliottii), have large tap root systems to help them withstand hurricanes. Other good choices for homeowners are the mahogany (Swietenia mahagoni) or the sapodilla (Manilkara zapota), Joyner said.
The gumbo limbo (Bursera simaruba), which like the live oak has a huge tap root system, is another favorite. Joyner described it as being “well-behaved in a storm.”
Slow-growing trees are less likely to break in high winds, and most flowering trees also are good choices because they don’t grow fast, Joyner said.
Conversely, the shallow-rooted ficus (Ficus spp.), popular as a shade tree, is not recommended for residential properties. The root balls of the ficus and its cousin, the banyan tree, can spread 25 feet or more. They are better suited for commercial properties and large open areas such as parks and schoolyards.
Trees less than a year old should be braced to help minimize the risk of toppling over in strong winds. But even if a hurricane uproots a tree, it doesn’t always mean it is dead. If the root ball was not damaged, the tree can be replanted.
Palms generate new roots from the trunk out, said Dale Holton, president of the Palm Beach County Palm and Cycad Society. It’s dead if the trunk is broken in half or if the crown of the palm _ the growing portion _ is twisted, Holton said.
Palms and slow-growing trees need a year or more to establish a solid root system, and for many South Florida communities that’s too long. We want our landscapes and we want them now. That’s why we plant exotics _ they are fast-growing, plentiful and cheap.
Despite its name, the silk oak is not an oak. It’s from Australia, and although it is not banned by the state _ as are other exotics such as the Australian pine, the melaleuca and the Brazilian pepper _ it should be, said Richard Moyroud, past president of the Palm Beach County Chapter of the Florida Native Plant Society.
Moyroud said another tree that should be avoided is the eucalyptus (Eucalyptus spp.).
“It’s another one of those trees that grows very fast and very tall, so it doesn’t stand up to the wind,” said Moyroud. He recommends the native bald cypress (Taxodium distichum) because it’s firmly rooted and has beautiful spring foliage.
He also likes the pigeon plum (Coccoloba diversifolia), which is good for small lots because it is well-proportioned and adapts well to many different soil conditions. “It doesn’t get too large, it has a compact crown and is highly wind-resistant,” Moyroud said.
Most landscape architects avoid rare or exotic trees in their designs.
“It would be a waste of money,” Nievera said. For coastal properties, he often recommends the green buttonwood (Conocarpus erectus), and the pitch apple (Clusia rosea) because they are both wind- and salt-tolerant.
Screen planting _ the placement of wind-resistant trees between the prevailing winds and trees not as strong _ also helps.
“If someone wants something other than those I recommend for this environment, I design a microclimate,” Nievera said. “Basically that’s a buffer zone, using the native plants so you create a protective environment for those that can’t survive.”
Landscape architects also advise homeowners not to plant large trees too close to the house. A rule of thumb is to use the tree’s height at maturity as a guideline. If a tree grows to 35 feet, plant it at least 35 feet from the house, Lang advises.
But energy efficiency also concerns homeowners, and they often want large shade trees near the house. A good compromise is the calophyllum (Calophyllum spp.), Lang said, because it’s a good shade tree with a fast growth rate. It’s a good choice for coastal properties because it is wind- and salt-tolerant.
At the former Kennedy family house in Palm Beach, Lang designed the landscape for new owners, John and Marianne Castle, to showcase the tropical style of the oceanfront property.
“There are no trees on the beach side [except) coconut palms,” Lang said. There are some Australian pines used as a hedge, kept trimmed low and tight.
He removed the melaleuca trees but did not replace them with other large trees. “Instead we put in tropical vegetation and a variety of medium palms on the leeward side,” he said.
They did keep a beautiful large banyan tree in front of the house. “But we greatly reduced its canopy,” Lang said.
