BY: Beau Brodbeck, PhD, Extension Specialist in Community Forestry & Arboriculture, Auburn University www.mobilecountymastergardeners.org
An unfortunate but common scenario that plays out time and time again goes like this: a homeowner purchases a home surrounded by large trees only to learn that many are in poor health, requiring costly maintenance or removal. There are two problems here that can be particularly distressing: first, the cost of unexpected tree maintenance, and second, the loss of trees that provide shade, beauty, and higher property values. In some cases, people have bought their homes because of the trees which are now a liability. Here are three tips to consider when evaluating trees around a new home.
First, evaluate the tree’s health. Tree health is a good indicator of past construction damage or trees reaching the end of their functional lifespan. A tree’s foliage and canopy are the best indicators of overall health. A healthy tree will have dense deep-green foliage that is evenly distributed around the canopy. Early signs of tree decline will include foliage that is yellowing and becoming sparse. Foliage may also become unevenly distributed or patchy, with leaves clumped in one area and large gaps in others. These signs can be subtle and highly variable, so it helps to find trees of the same species and size to use for comparison.
A more obvious and problematic symptom of progressing tree decline are dead limbs at the top or outer margin of the canopy. Ignore dead limbs inside or on the lower portions of the canopy. These are naturally shed due to shade from the tree’s own growth or surrounding vegetation. Dead branch tips, however, especially as larger branches die off, signal the tree is dying back. It is important to note that depending on the tree species, age, and causal damage, this dieback process can progress quickly (1 to 3 years) or over a decade or more. With early intervention, it might be possible to reverse tree decline using proper tree-care techniques, which could be costly. If the top-quarter or more of the tree is dead, removal is inevitable.
Second, evaluate trees near the home for defects that could increase risk of failure. Purchasing homes that have potentially dangerous trees in the landscape, especially on the storm-prone Gulf Coast, can be a costly mistake. Trees in landscapes are often damaged during the construction process. Common damage includes cut roots for foundations, underground utilities, sidewalks, driveways, or irrigation systems. If roots have been cut within the tree’s dripline, future tree health and possibly stability are issues. Other construction related problems include soil compaction caused by driving or stockpiling materials within the tree’s dripline or burying roots with grade changes. Note that newly-installed turf and landscaping can mask many of these problems.
Evaluating tree health is a good method for determining if there has been construction-related root damage. However, be aware that some trees might show only subtle signs in the first year, becoming more obvious as time progresses. As a result, you need to inspect trees carefully and ask about previous construction practices.
There are other tree defects, not related to construction, to look for as well. These include:
· Lightning scars: look for strips of missing bark running the length of the tree
· Cracks: look for deep fissures in the wood, especially in the crotches of forked trees
· Decay: evidence of internal decay includes fungal fruiting bodies (conks and mushrooms), missing bark, oozing wounds, and carpenter ants.
· Large cavities: cavities extending more than a third of the tree’s diameter can be problematic
· Sawdust: boring insects in trees will leave fine sawdust on the bark and tree base
Finally, get a second opinion. Evaluating tree health, and especially tree risk, can be a complex and highly subjective process, built on the knowledge and experience of the evaluator. If you have doubts, consider hiring an International Society of Arboriculture Certified Arborist who is Tree Risk Assessment Qualified to evaluate the tree’s health and risk potential. A few hundred dollars up front could save thousands of dollars and, more importantly, the heartache of removing trees you hoped to enjoy. This knowledge can help you decide if the trees are going to be a valuable part of your landscape in the years ahead or a potential liability. Finally, this information can prove useful when negotiating the sale price of the home.
For a more detailed guide to evaluating trees for risk please see this article: https://www.aces.edu/blog/topics/disaster-home-family/restoring-storm-ravaged-trees-step-by-step-guide-to-examining-your-tree-for-safety/. To find a Certified Arborist in your area go to treesaregood.org.