Let your plants help your home be hurricane safe!By LariAnn Garner (LariAnn)
June 11, 2008
Running interference for you
As a veteran of several hurricanes, including hurricane Andrew, I am acutely aware of the damage they can cause to your home and property, not to mention your plants and trees. If anything good can be said to come out of such a horrifying experience, though, it is observing which plants and trees did not get destroyed by the storm. Some do survive, and that knowledge can be used to craft a landscape plan that provides real protection to your home while giving you an attractive planting. While the suggestions that follow are geared towards people living in Florida or other areas where the plants and trees mentioned can grow, the general idea can be implemented with other durable trees and plants as well.
Blowin' in the wind
To begin, you need to know first what the major damaging components of a cyclonic storm are. They are wind, wind-blown debris, wind-driven rain and flooding. You can employ specific plants and trees to help with the first three. Mitigating flood damage is not something your plants can help with, although there are site design and preparation steps you can take to help you with this one.
The major home preparation routine that people perform when a storm approaches is the raising of hurricane shutters or the fastening of plywood over their windows. The right plants and trees can stand in to provide this kind of protection, either reducing the need for hurricane shutters or providing an extra margin of safety. What you want to accomplish is to diminish the wind velocity that actually impacts your home. If the storm is packing winds over 100 mph, you will want to decrease that to 40 mph or below. This can be done with the right type and quantities of wind-breaking trees and shrubs, strategically located around the home in the most vulnerable areas. In my experience, the best plants for this are the Sabal Palm (Sabal palmetto) and Saw Palmetto (Serenoa repens). These two are native to Florida and have very durable leaves that are not likely to tear off in a severe storm They also have dense enough heads of leaves to serve as good windbreaks. The key is tree/shrub height. You don't want the Sabals or other trees to be too tall since you want the head of leaves to provide protection at window to roof level. All of the plants and trees you choose must be strong enough to withstand hours of hurricane or tropical storm force winds and rain.
Three lines of defense
Your first line of defense, nearest to your property line, will consist of large-culm clumping bamboo and reclinata palm clusters (Phoenix reclinata). If possible, the reclinatas should be on your fenceline to the east or west of your property, and the bamboo inside the fenceline in the same areas. Instead of bamboo, you may choose to plant Cypress trees (Taxodium). These plantings will take the brunt of the hurricane force winds and pass a somewhat slowed wind velocity to your second line of defense plantings. By the time the wind comes through your final line of defense, it may still be turbulent but will no longer be approaching at a damaging speed.
Working closer to your house, you should consider more Cypress trees and/or Live Oaks (Quercus virginiana). These are extremely durable and resistant to breaking, and they have fine or small leaves that grow back quickly after storms. These should be planted in groups such that they can provide a wind deceleration zone as your second line of defense after your perimeter beds. The objective here is to attain groups of tough trunks that will divert wind and block large flying debris, especially from major storms. Each grouping should have trees of varying heights in a pleasing arrangement. Good understory plantings for these trees are Cocoplum (Chrysobalanus icaco) or Cat Palms (Chamaedorea cataractarum), if desired.
In the picture at left, observe the damage to the coconut palm and the Royal palm with no fronds left, while the Cypress tree stands practically unharmed. Note that this picture is not an example of a hurricane protective planting, but merely an example of how a Cypress tree fared in hurricane Wilma as compared to other trees nearby.
For your final line of defense, a preferred planting arrangement would be a bed that includes several Sabal Palms of various heights in the center of the bed, surrounded by a perimeter planting of Saw Palmettos. Your beds should be arranged so as to protect several window areas if possible, or multiple beds can be employed. Other plants can be included in the bed for added landscape interest, but the two palm types are the foundation for slowing the wind as well as for catching windborne debris. This final line of defense should result in the wind speed being low enough to be below the damaging threshold.
Hold onto your hat!
Roof protection is integral to your plan. It is as simple as taking steps to insure that the wind velocity hitting your roof is not enough to lift shingles. This is accomplished by placing relatively short, durable palms, like the Sabal, in strategic locations around your home. The palm heads should be high enough to blunt the wind force coming over your roof deck. This will serve to break the incoming wind and decrease the suction that would lift your shingles, roof sheathing, or deck off. Other palms like Livistona or Phoenix can perform in this manner; the key is that the palm must be strong enough to remain standing and also to retain leaves during the storm. However, even somewhat less durable palms can provide the proper protection in category 2 or 3 storms. My experience with hurricane Wilma and Katrina showed that Queen palms, normally not noted for hurricane resistance, kept the wind velocity low enough over my roof that not one shingle was out of place at storm's end. By contrast, many home roofs in the area needed a lot of repair work after Wilma. I believe that my roof would have suffered much less damage from hurricane Andrew had I planted Sabal palms to the southeast and southwest of the home.
To prepare for a storm, some folks will trim off most fronds from their palms, reasoning that if the palm has less leaves, it will be less likely to be toppled or damaged. This "hurricane trimming" may be of value for palms that are not hurricane resistant. However, you do not want to "hurricane trim" your protective palms, as that would reduce or eliminate their ability to serve in a protective role.
Build on this guidance
The suggestions contained in this article are based on my experiences and observations and should be considered a starting point on the use of landscaping for home hurricane damage mitigation. I recommend strongly that you consult with your local Extension Agent as well as competent landscape professionals for additional specific details and other points of view on this topic. By so doing, you can become informed enough to make the right decision for your particular home situation.
A good reference is the U. of Florida publication, "Assessing Damage and Restoring Trees after a Hurricane", especially the Wind Resistant Tree List, Page 12
Photo credits: Public domain and LariAnn Garner