Hurricanes, Storms and Your Landscape

  Here is an article I co-authored with my good friend Mark Torok from the Florida Forest Service (FFS) tackling the tough questions around tree care and storms.

Hurricanes, Storms, and Your Landscape

by

Mark Torok, FFS Senior Forester

Mark Williams, Treemendous Consulting Group

Living in Florida, sooner or later, given its history, your landscape is going to be exposed to high winds either from a hurricane, tornado or a storm. So, what can be done to minimize wind damage in your Florida landscape?

 

For starters, have your existing trees inspected annually and/or structurally pruned by an ISA (International Society of Arboriculture) certified arborist who is also licensed and insured. To find an ISA certified arborist in your area, you can use the “Arborist Search” on the ISA website at http://www.isa-arbor.com/findanarborist/arboristsearch.aspx. Having your trees inspected annually (risk assessment) and structurally pruned every 2-5 years will help the trees become more wind-resistant by eliminating or minimizing structural defects such as cross branching, decay, codominant stems, deadwood and included bark in the trees.

 

If you are thinking about redoing and or enhancing your landscape, plant more wind resistant trees. Just like people, all trees are not the same; some are more wind-resistant than others. In general, trees species that are wind resistant are also good compartmentalizers. Good compartmentalizers are tree species that can recover well from wounds and that seal them off effectively preventing the spread of decay. Even trees that are in the same family can vary on how well they compartmentalize. For example, live oak trees are very wind resistant and great compartmentalizers while laurel oaks/water oaks are very poor compartmentalizers and not very wind resistant trees.

 

Another way to make your landscape more wind tolerant is planting trees in groups. In a natural forest setting, winds normally blow over a stand of trees instead of blowing through them unlike the total exposure faced by an individual, open-grown tree. Grouping trees together in tree islands/communal plantings simulates how trees grow naturally and mimics the buffering effect of trees within a natural forest community. But remember to use minimum tree spacing requirements which are typically planting trees at least 15-20 foot on center for tree species that develop large canopy crowns. In order for a tree to develop proper taper a certain amount of wind exposure is also necessary. Some examples of Florida native tree species that are often found growing in groups include slash pine, bald cypress, live oak and sabal palm.

 

Addressing any root defects that may be present before planting will also aid tree establishment and help ensure a well anchored root system.  Some additional information about tree root pruning is available at: (http://hort.ifas.ufl.edu/woody/roots.shtml). Remember to plant your tree slightly above grade, install the recommended bracing system and to remove any circling, plunging and girdling roots that are present. The use of Florida Grade No. 1 (Grading Standard for Nursery trees set by FDACS) or above rated trees is also recommended as these trees are of high quality with excellent structure. Trees of this grade typically have greater vigor, establish faster and are free of structural defects commonly present on poorer quality/lower grade trees. Some additional information on proper tree planting and bracing is available at: ( http://hort.ifas.ufl.edu/woody/planting2.shtml).

 

 

Here are some high wind resistant native south Florida trees:

 

Gumbo limbo              Green buttonwood     Geiger tree

White stopper             Redberry stopper        Spanish stopper

Lignum vitae                Dahoon holly                Krug’s holly

Black ironwood           Bald cypress                   Pond cypress

FL silver palm              Cabbage/Sabal palm   FL thatch palm

Key thatch palm          Myrtle oak                     Live oak

Sand live oak

Here are some medium-high wind resistant native south Florida trees:

 

Pond apple                    Satinleaf                        Royal palm

Pigeon plum                  Wild tamarind             Sweetbay magnolia

Mastic tree                    Paradise tree               West Indian mahogany

 

References

Duryea, M.L. 2008. Trees and Hurricanes. Website: http://hort.ifas.ufl.edu/treesandhurricanes/index.shtml of the University of Florida Cooperative Extension Service. Gainesville, FL.

 

Gilman, E. 2005. Tree selection for landscapes. Website with 680 Tree Fact Sheets: http://hort.ifas.ufl.edu/woody/planting/TreeSelectionIntroduction.htm of the University of Florida Cooperative Extension Service. Gainesville, FL.

 

Crawford, P. 2005. Florida Gardening Series, Volume 3 – Stormscaping: Landscaping to Minimize Wind Damage in Florida. Color Garden Inc. Canton, GA. 168 pp.

How to Prevent Tree Damage from Storms

Preventing damage to mature tree canopy due to storms starts with ensuring that proper tree pruning has been scheduled and completed by an ISA Certified Arborist and or company. Removal of existing hazards (cross branching, hanging limbs, deadwood etc.) and establishing a central leader when applicable should be the main priorities. Normally canopy trees should be inspected at least annually for the presence of any hazardous defects. "Hurricane" trimming of trees is not necessary every year and can actually be harmful be removing much more canopy then is necessary weakening your trees. The rule of thumb for scheduling structural pruning is once yearly for trees that are 1-7 years of age, every 1-2 years for trees 7-14 years of age and 3+ years for trees 14 years and older. For trees that have been storm damaged tree evaluation for hazard abatement is a must. Only utilize a trained ISA Certified Arborist and or company to perform this type of pruning.

For some additional tips on structural pruning for trees please see the following references:

Pruning Young Trees, Restoration Pruning, Mature Tree Pruning

How to Protect Trees During Construction

Trees are a valuable resource and when planning construction on a site where they are present, care must be taken to avoid any potential for damage. The best time to incorporate tree protection measures is before construction has begun during the early planning stages. At this point final designs typically haven't been completed leaving multiple options to incorporate and protect trees as part of a sustainable landscape/construction design process. As damage can occur to a tree's trunk, canopy and root zone normally tree protection zones are created that protect all three areas. The zones are typically laid out and defined on construction plans as areas where no construction activities can occur, no equipment can be stored and no chemicals and or construction debris can be placed. A tree protection barrier is also a typical requirement that must be installed prior to construction onsite and maintained throughout the project.

For some additional information on tree protection strategies please visit the following website:

Tree Preservation During Land Development