Sources:

http://gardeningsolutions.ifas.ufl.edu/plants/trees-and-shrubs/trees/restoring-trees.html

Restoring Trees After a Storm


Not all trees damaged in storms need to be removed. Some can be restored back to health. This topic is complicated, and retaining the services of a qualified professional is recommended. But can a homeowner tell if a damaged tree can be restored?

To be a good candidate for restoration, a tree should not have cracks in its major limbs or trunk. Its roots should not be exposed or lifted out of the soil. In addition, the branches and trunk structure need to have been strong and healthy prior to the storm. This means that the tree does not have multiple trunks, co-dominant stems, bark inclusions (weak unions between major branches and the trunk), or large amounts of decayed wood.

(To find out if your tree has a bark inclusion, visit Dr. Edward Gilman's website, Landscape Plants, and look at normal and bark-included branch unions. Dr. Gilman's site has extensive information on tree care, with plenty of descriptive photos.)

The following signs should tell you if it is even possible for a hurricane-damaged tree to be restored.

The canopy is defoliated or damaged, but there are still lots of branches. Trees that lose their leaves or break small canopy branches in a hurricane are usually not dead. New foliage may appear by the following spring. A tree that is decay-resistant (especially impervious to the spread of fungal organisms following an injury) can lose up to ¾ of its small canopy branches and still recover. Trees flooded with salt water during a storm will also often lose their leaves. These should be irrigated with fresh water to wash salts through the soil if possible soon after the storm.
Only small branches are dead or broken. Trees with broken branches less than 4 inches in diameter can easily be pruned and have a good chance of recovering.
Some major limbs are broken, but it's a decay-resistant species. Some species of trees are more decay-resistant than others. Health specimens of decay-resistant species can be restored even with some major branch breakage and could recover well after a hurricane. Younger trees with a diameter of less than 10 inches are easier to restore than older, larger trees.
A leaning or fallen tree is small. Only trees that were recently planted or have a trunk diameter smaller than 4 inches should be staked or replanted if they have fallen over during a storm.

How to Re-Plant a Small Tree That Has Fallen Over

To stand up a small tree that has fallen over during a hurricane, follow these steps.

Keep roots moist.
Make the hole large enough to fit the tree's roots in.
Cut jagged or torn roots cleanly.
Pull tree upright.
Fill in the hole with the soil you've removed from it.
Water with 3 gallons per inch of trunk diameter, three times per week.
Stake the tree. Adjust stakes regularly and remove them when the tree is stable.

Cleaning the Canopy

To begin the restoration process, follow these steps immediately following the storm.

Remove dead, broken, and hanging branches.
Wait and see how the tree does the following year.
The tree may recover if sprouts appear along branches later in the year or the following spring.

Restoring a Palm

Palms grow differently from other trees. Restoring a storm-damaged palm takes careful work. Hire a qualified professional, or follow these guidelines to get your palm back to optimal health:

Remove hanging or dead fronds. These could fall and hit a person or damage property. Dead fronds are entirely yellow or brown in color.
Remove fronds that cover the bud. Broken fronds crossing the top of the palm can prevent the growth of new fronds that will restore the canopy.
Leave any bent, green fronds (even if they have yellow or brown tips) that are still attached to the tree, so long as they are not covering the bud. These fronds will help the palm store energy until new foliage emerges. Then you can remove the bent fronds.
Establish a fertilization program to correct nutrient deficiencies. When palm fronds that are still alive and attached show severe yellowing, it's a sign that the palm may lack nutrients such as potassium or magnesium. Do not remove these yellowed fronds; they are still providing energy for the tree. Instead, establish a regular fertilization regime specific to palms.

Sources:

http://gardeningsolutions.ifas.ufl.edu/plants/trees-and-shrubs/trees/preparing-trees-for-hurricanes.html

Preparing Trees for Hurricanes


Shade trees such as the live oak pictured here should be trained to one dominant trunk well up into the canopy. This makes the tree strong against the forces of storms.

Hurricanes and tropical storms hit Florida almost every year, often causing extensive damage to landscapes. But you can easily make your landscape more hurricane-resistant, so that it's less likely to suffer damage during a major storm.  

Selection

The best way to protect your landscape from hurricane damage is by planning it carefully. Choose species that are more wind resistant, and plant them away from utilities and structures. Select trees from the nursery that have straight (not circling) roots, one dominant trunk, and branches that are spaced apart from each other. If your trees don't have these attributes, they should be pruned so that they do.

A tree more likely to survive storms is compact, with a low center of gravity; a strong, sturdy trunk; and a deep, symmetrical root system. The native live oak is a great example of a "survivor" tree, given the right environment and care during its life.

On the other hand, a more vulnerable tree during storms is one with a high center of gravity, a dense canopy, a decayed trunk, two or more trunks, or shallow roots. Shallow roots result from shallow soil or a high water table.

Tall, slender pine trees that were part of a forest before suburban development are susceptible to storm damage. These trees relied on one another for wind resistance and support during storms. Without each other, they are unprotected from storm damage. Consider removing tall, slender trees from your landscape for safety and replacing them with trees that are known to be sturdier during storms. Existing trees with severed root systems from construction can also fail in storms by falling over. Consider reducing their size or removing these weak trees.

Remember that any tree is more susceptible to toppling during a storm if it suffers from construction damage to roots, poor growing conditions, small root zones, and disease or insect problems.

Planting

Plant trees from the "Highest" and "Medium-High" UF/IFAS Wind Resistance lists and match these to your site conditions. Give trees adequate rooting space with no obstructions (sidewalks, buildings, and streets). For small trees, there should be at least 3 meters by 3 meters unobstructed around the trunk; for large trees, provide at least 10 meters by 10 meters. Consider planting trees in groups as opposed to individually. This will make them more wind-resistant.

Trees planted in the last five years and very old, large trees are the most susceptible to hurricane damage. Young trees don't have an extensive root system to anchor them in wind, while old trees often have some decayed and weak branches. Large trees should be evaluated by a professional for defects that are not visible from the ground.

Pruning

Correct pruning is the most important part of helping trees survive hurricanes. Train young trees so they develop a sturdy, well-spaced framework of healthy branches along a dominant trunk. Maintain this form as far up into the tree as possible by reducing the length of competing stems and branches.

For trees larger than about 15 feet tall, hire a professional to prune your trees before the hurricane season. The qualified professional will remove dead branches that can fall on houses, cars, and people. Overly long branches should be shortened and branches with cracks removed or shortened. Branches with the same diameter as the trunk will be shortened and the outer edges (not the interior) of the canopy will be thinned, making your tree less likely to be blown over. Low branches that are close to your roof should be removed or shortened, as well. Be sure to have your trees evaluated by a professional about every two years.