Hurricane and Wind-Damage Prevention

What's in the Eye of the Storm?

Having lived for many years on both coasts of Florida and experiencing several direct or near-direct hurricane hits, I know that certain types of trees survived better than others. Pines are often storm victims. When an ice storm hit northern Mississippi back in the 1990s, it brought pine after pine down on the roads' power lines, virtually stranding the population for weeks. Ice has broken, felled, and twisted pine trees in my own Georgia back yard.

Crawford asks why, following a hurricane, "are some trees down and others still standing? They were all subjected to the same winds, and although many different factors affect a tree's stability, most important is the tree's wind tolerance. Some trees, like ironwoods, have very strong wood and a root system that goes deep into the ground to keep the trees stable. Their canopies are loose enough to let the wind blow through them rather than blowing them over. Other trees have shallow root systems, weak wood, and dense canopies. These three factors cause tress to fall easier."

Not Much Hope in a Category 5

No plant, says Crawford, can stand up to 160 MPH winds, but not many storms are actually that strong. In a Category 3 storm, however, she says that "many trees will survive those winds, particularly if [the location] is away from the [storm's] eye." Hence, she suggests intelligent planting. "Know the wind tolerance of every plant you buy," she writes. "And stick to wind-tolerant trees for the areas where they could fall on your house."

Palm trees, obviously, are popular in Florida and Southern coastlines, but not all palms are wind-tolerant, Crawford says. "Queen Palms are one of the most common palms used in south and central Florida. They have very little tolerance for wind." In one storm, some were bent over to the point where they became dangerous. She also points out that native Florida trees do better in storms.

Wind Tolerance

"Native trees were present in Florida before Christopher Columbus discovered America," Crawford says. "Exotics are trees that have been introduced into Florida since 1492. Dr. Mary Duryea found that the native trees fared better than exotics after Hurricane Andrew. 'Native tree species … were the best survivors in the wind … 34 percent of the exotic trees were still standing after [Hurricane Andrew], while 66 percent of native trees were standing.'" However, adds Crawford, this may not be true for all of Florida, including the northern part of the state. "Water Oaks and Laurel Oaks, both natives, were two of the worst trees in these areas during the four storms of 2004," she said. Some exotics also held up well, including Date Palms. "Some exotics," she notes, "are from areas of the world that are quite windy and are well-adapted to it. To be on the safe side," she recommends, "check out the trees' wind tolerance before assuming that all native trees stand up beautifully in hurricanes."

Florida trees that Pamela Crawford says are wind tolerant include the Bald Cypress, Crepe Myrtle, Dogwood, Gumbo Limbo, Ironwood, Japanese Maple, Live Oak, Southern Magnolia, the Canary Island Date, and Foxtail Palms. Other palm trees that she suggests include the Pindo, Pygmy Date, Royal, Sabal, Saw Palmetto and Thatch palms.

The Three Worst Offenders

Crawford named several trees as the three top public enemies for causing damage in hurricanes. The first is the Australian Pine. "They not only fall easily, but the root ball comes out of the ground, leaving you with a mass that weighs tons and often costs thousands of dollars for disposal." These, she says, grow in the frost-free regions, "but with the current warming trend, their range is expanding towards the north." She recommends that these trees be removed if they are within falling distance of a structure.

Dr. Robert Loflin, natural resources director for Sanibel Island, told Crawford that it cost $6 million to haul and burn the trash after Hurricane Charley. "Sixty percent was the Australian Pine," he said. The cost per resident was $553. Dr. Duryea also reported that 96 percent of these trees fell in Hurricane Andrew, but millions of them are still standing in south Florida.

Number two on Pamela Crawford's list for the worst trees is the Ficus Benjamina. She says that after Andrew, "we learned that the Ficus not only blew over easily, but also cost a fortune to remove." But many were replanted. She reports that when Hurricane Katrina passed over Ft. Lauderdale with only 75 MPH winds, "several people were killed when these monster trees crushed their cars. One golf club in Palm Beach County," she adds, "spent $160,000 just removing these trees, to say nothing of repairing the damage done to whatever was underneath."

The third tree on her worst list is the Laurel Oak, more prominent in the northern part of the state. "If you have one of these within falling distance of your house," Crawford warns, "remove it, especially if it is an older tree. Laurel Oaks are weaker and shorter lived than Live Oaks, and the four storms of 2004 proved that the older ones were particularly dangerous. Officials from Santa Rosa County, which was badly hit by Ivan, estimated that 50 percent of the tree debris was from Laurel Oaks and Water Oaks."

To these three or four offenders Pamela Crawford adds as worst damage-causing trees the Ear Leaf Acacia, the Queen Palm, Redbud, Cherry Laurel, Drake Elm, Sand Pine, and the Tabebuia. She also notes that other popular trees, such as the Black Olive, have low wind resistance. Dr. Duryea found that after Andrew, only 68 percent of Black Olive trees were still standing. While living in Coral Gables, this writer's home was on a street lined with palm trees. A blight hit the trees and they died, and the city planned to replace them with new palms. But palms are messy trees, with fronds frequently falling, so our neighbors all got together and asked the city to replant with black olive trees. That was more than 30 years ago, but in a direct hit, they could be tall enough to hit the house.

Preventing Damage

Crawford notes that trees fall for a number of reasons. She lists 16, ranging from failure to properly prune trees to planting them in areas of wet soil. She even cites damage from weed-eaters, where the cutting blades have gouged into the base of the tree when the grass around the trunk is being trimmed. She notes that trees with two main trunks easily split, and that trees planted in a clump stand up better than a single exposed tree. Trees planted near pavement fall over faster than those planted in the open, as do those planted near a building or residence. The age of the tree can also be a factor. But the primary factor remains wind tolerance.

Could better tree management reduce the cost of storm damage in future hurricanes? Many scientists and horticulturists believe it could. Should property insurers take tree types and locations into account when underwriting? Certainly many insurers are now inquiring about the breed of dogs kept as pets, and may fuss over the owners of pit bulls or other "notorious" beasts. Why not fuss over a towering Australian Pine that is likely to come crashing down on an insured's home in a strong wind? Why not take into account the care, age, and size of trees that could cause damage to the structures being insured? Pamela Crawford's book should be read by all Florida residents — and most certainly by any Florida insurer/underwriter.

Perhaps trees are a basis for claim subrogation. Usually a tree that falls from one person's property to the roof of the house next door is seen as a first-party loss. But tort laws take into account a factor called "foreseeability." If homeowners were made aware of the hazards of certain types of trees, such as the Australian Pine, and yet continued to allow such tall trees to remain a hazard to their neighbors as well as to themselves, there might well be a valid basis for subrogation. As windstorm deductibles in Florida are extremely high, insurers owe it to their policyholders to seek out any potential subrogation source that might return some of that deductible to the insureds.

Ken Brownlee, CPCU, is a former adjuster and risk manager based in Atlanta, Ga. He now authors and edits claim-adjusting textbooks.