Evaluating your trees before hurricane season

By Beau Brodbeck, Ph.D., Extension Specialist in Urban Forestry, and Jack Rowe, Regional Extension Agent / aces.edu and MobileCountyMasterGardeners.org

Trees are a part of life in the South. Without them, our cities, towns and neighborhoods are much less enjoyable. Hurricanes are also a part of life in Alabama. Based on historical records, coastal Alabama is brushed by a hurricane every 2.5 years and receives a direct hit every nine years. It is not a matter of “if” but “when” the next storm will impact our urban forests.

Trees are large and long-lived plants. Unable to escape from dangers, they literally stand their ground against the forces of nature like the weather. In addition, street, park and lawn trees are under constant assault from human-related pressures — construction, automobiles and utility-line clearance, for example.

The first step toward safer trees is taking responsibility. Urban trees are like any other asset. Better management increases return and minimizes risks. Be proactive throughout the life of your trees. Examine your trees at least once per year and after major storms.

There are three simple steps to having safer trees: evaluating, treating problems quickly and removing a tree when its risks outweigh its value. The following are key concepts for evaluating tree safety in your landscape.

Step 1: Evaluate potential targets that a tree or tree part could strike. Targets can include houses, fences, cars or people. Removing targets, such as trampolines or playground equipment, is an easy solution to reduce risk.

Step 2: Identify the tree species. Knowing this can provide important clues about your tree’s safety because some species are prone to certain defects. Once you know the species, you can research the tree’s specific traits that make it desirable or problematic. Visit ufl.edu for tips on establishing a wind-resistant urban forest.

Step 3: Evaluate the roots. While all the tree’s roots are important to the health of the tree, roots located within eight feet of the trunk are critical to tree stability. Most root problems are not visible; instead, remember past work (e.g., trenching for underground utilities, new construction under the tree’s dripline, etc.) that cut or damaged roots. Even shallow trenches can be a problem as 90 percent of a tree’s roots are located within two feet of the surface. Look for leaning trees with heaving (or mounding) roots on the opposite side of the lean. Leaning trees pose serious risks. Check for root rot by looking for mushrooms or cavities around the base of the tree.

Step 4: Evaluate the tree’s trunk. Serious problems include cracks caused by either twisted trunks or in the union of forked trees. Look for evidence of decay in your trunks. Common signs include sprouting mushrooms, oozing wounds, loose bark, carpenter ants or cavities. Most trees have some decay; the extent and location of the decay are key. Cavities or decay at the union of large branches is especially troubling. Finally, forked trunks with tight, “V-shaped” unions can increase the risk of failure in high winds.

Step 5: Evaluate the crown. Begin by looking for hanging or dead branches. Then look for cracked branches and decay or cavities in larger branches.

Remember, there is no such thing as a perfect tree. All trees have defects and/or decay that can lead to failure. The key is minimizing the risks to retain trees to maximize the value they bring to our landscapes.

If a second opinion is needed, it’s critical to hire professionals with the appropriate knowledge and credentials. All too often we see poor pruning practices, such as topped trees, sold as “hurricane pruning,” which drastically shortens the life and future safety of trees. The International Society of Arboriculture (ISA) certifies arborists and has a Tree Risk Assessment Qualification (TRAQ) that helps customers ensure professionals are knowledgeable on the latest science-based techniques (to find a certified arborist near you, visit TreesAreGood.org).

Spring Garden Events

What: Homeowner Tomato Workshop

Where: Online

When: Tuesday, April 13, 6-7:30 p.m.

Cost: Free

Register: aces.edu/go/1877

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Where: 700 Forest Hill Drive, Mobile (accessible through trail #1)

When: Daylight hours, daily

Cost: Free, but donations appreciated

More info: mobilejapanesegarden.com

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