Our thanks to Harold Bubil and the Herald Tribune Media Group for informing the Sarasota community about how to protect our trees before, during and after hurricane season.
Hurricane Irma may be fading from memory in much of the state, but Florida homeowners continue to cope with the storm’s fallout.
Especially in their landscapes. As crews slowly pick up roadside plant debris, owners are noticing patches of light brown in their oak trees, where partially broken branches are hanging until they eventually fall.
Those branches, and the ones from which we made such tall piles of debris, are a good thing, said Sarasota landscape architect Michael Gilkey in a recent interview.
“It’s the beauty of nature,” Gilkey explained, noting that he has five oak trees at his home on the Sarasota mainland. “The live oak in my front yard … was swaying more at 3 p.m. on the day of the storm than it did at 9 p.m., when the storm came through.
“I was sure I was going to lose my tree. But every hour, the tree lost more leaves, more small branches, and it kind of cleaned and thinned itself so that when the big winds got here, there was less mass for that wind to pull against. That is not an accident. That is how nature thins itself out so it did not have a catastrophic fail.”
Gilkey is among those tree experts who recommend against severe pruning of oak trees for dramatic uplighting.
“People love to hollow-out trees. You remove all the interior branches and you light them up because the branches are so beautiful. That is extremely unhealthy for that tree.”
He said leaves “are acting as a parachute to slow the swing of the limb” in a hurricane. “When you take the branches and leaves off the interior of the tree, all you are left with is a long branch with a tuft ball of foliage on the outside, which causes it to swing way more than if it were foliated. That also will add to the failure of that branch during a wind event.”
Fort Myers arborist Rick Joyce, who consults at the Edison & Ford Winter Estates, calls this practice “lion-tailing.”
He said live oaks, which are resistant to windstorms, often are over-pruned for “that dramatic effect of those long branches, but when you put all that wind right on the branch tip, that is not a good pruning practice. In the wind, it is whipping with that tuft of foliage on the end.” It is not unusual, he said, for the branch or limb to break off.
Joyce said the biggest threat to trees’ survival in windstorms is poor structure, which often leads to disease and weakness. Proper pruning is the solution.
“The biggest single thing any owner can do for their trees is high-quality structural pruning,” Joyce said. “Do what you can with what you have in an existing tree to build the strongest branch structure you can. It can really make a difference in how well those trees perform in higher winds.”
Specifically, he said, remove dead branches, crossing branches and weak connections where limbs depart from the trunk.
“The most problematic, common weak connection is where a tree has ‘co-dominant leaders,’ instead of having one singular strong leader (limb) that branches into multiple leaders. If those connections are not U-shaped, but instead are closely connected in a V-shape, there can be ‘included bark’ in the connection.
When building a new house or renovating a landscape, Gilkey and Joyce said, proper tree selection can prevent problems when the next windstorm strikes.
Sabal, or cabbage, palms are the heartiest variety of palms, while oaks and gumbo limbo trees perform well in high winds. Exotic species, such as the Mysore fig that is now lying on its side at the Edison property, may come from areas where windstorms are not common, and have not built a resistance to them.
“Trees that grow in the hurricane areas see these storms on a periodic basis and have figured ways to adapt to them,” said Joyce, who is a past-president of the Florida Native Plant Society.
“The plants that are native have been exposed to hurricanes through the generations and have evolved those systems to be able to deal with them,” he said.
Gilkey, who said gold trees and older laurel oaks were most commonly felled by Irma in Sarasota, advises homeowners to watch for signs of fungus, especially in palm trees.
“The biggest problem we will have with palm trees (after Irma) is secondary fungal infections of trees that were damaged by the wind,” he said. “You may not see for another month or two.”
In the wake of Irma, Gilkey emphasizes the importance of caring for larger canopy trees.
“Have a certified arborist come out every two years or so and make sure your trees are healthy, and that they are not a hazard to come over” in wind events, he said. “That can be exacerbated by poor drainage or building a structure nearby that impacts the roots. That might have been done by a previous homeowner, and you might not even know it.
“The tree might look completely healthy to the naked eye, but you get an arborist come out and he discovers cavity rot, or this tree has too much weight on one side. They can start a management plan to mitigate for that, by reducing the weight of the tree, or removing hazardous branches that have a poor connection, so that when you do have a wind event like this, the trees don’t fail.”
The University of Florida studied tree performance following hurricanes in the 1990s and 2000s and published the results in “Wind and Trees: Lessons Learned From Hurricanes,” by Mary Duryea and Eliana Kampf.
Among the findings:
• The higher the winds, the more likely it is that trees will break or topple.
• Some species resist wind better than others. “Consider removing over-mature and hazardous tree species that have demonstrated poor survival in hurricanes,” the study’s authors wrote.
• Palm species survive hurricanes better than broad-leaved and conifer trees (pines).
• Trees that lose all or some leaves in hurricanes are not necessarily dead.
• Native trees survived hurricanes better than non-natives in South Florida.
• Older and unhealthy trees are more likely to fail in hurricanes.
• Well-pruned trees survive better than poorly pruned or unpruned trees.
• Trees with poor structure or included bark are more vulnerable in high winds.