Isaias Clean-Up: Tree Evaluation After A Major Storm

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As Hurricane Isaias wreaks havoc on the Eastern Seaboard, landscapers know that once the dust settles, they’ll be involved in clean-up activities on client properties. And while some practices are cut and dry, tree evaluation can be a tougher issue. Since not all trees damaged in storms need to be removed, how can you tell if an affected tree can be restored?

Can It Be Saved?

According to the downloadable Tree Care Kit from Texas A&M AgriLife Extension, the good news is that “trees have an amazing ability to recover from storm damage.” Here are areas they say to assess:

  • Are major limbs broken? If most of the main branches are gone, the tree may have little chance of surviving.
  • Has the leader (the main upward-trending branch on most trees) been lost? In species where a leader is important to upward growth or a desirable appearance, saving the tree may have to be a judgment call. The tree may live without its leader, but at best it would be a stunted or deformed version of the original.
  • Is at least 50% of the tree’s crown still intact? This is a good rule of thumb on tree survivability.
  • How big are the wounds where branches have been broken or bark has been damaged? The larger the wound is in relation to the size of the limb, the less likely it is to heal, leaving the tree vulnerable to disease and pests. A 2″ to 3″ wound on a 12″ diameter limb will seal over with new bark within a couple of years.
  • Are there remaining branches that can form a new branch structure?

Being based in Florida, Gardening Solutions, a program of the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) has a lot of hurricane-specific advice. They say for a tree to be a good candidate for restoration, roots should not be exposed or lifted out of the soil. Additionally, there should not be cracks in the tree’s major limbs or trunk. In other words, the tree should not have multiple trunks, co-dominant stems, bark inclusions (weak unions between major branches and the trunk), or large amounts of decayed wood.

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Photo: Dr. Edward Gilman, UF/IFAS

According to UF/IFAS, the following signs should tell you if it’s 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 if possible soon after the storm to wash salts through the soil.
  • Only small branches are dead or broken. Trees with broken branches less than 4″ 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″ 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″ should be staked or replanted if they have fallen over during a storm. To replant, cut jagged or torn roots and keep them moist. After planting, water with three gallons per inch of trunk diameter, three times per week.

Restoring a Palm Tree

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Bismarckia nobilis, Silver Select Bismarck palm. Photo: Chris Runge, Landscape Concepts

Those in zones with palms know they grow differently from other trees, so restoring a storm-damaged palm takes careful work. Follow these guidelines from UF/IFAS to get a palm back to optimal health:

  • Remove hanging or dead fronds. Dead fronds are entirely yellow or brown in color. These could fall and hit a person or damage property.
  • 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.

For pictures and more tips on treating damaged and broken trees, visit the UF Landscape Plants site from Dr. Edward F. Gilman, Ph.D. Professor Emeritus, Environmental Horticulture.

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