Photo by Beau Brodbeck
Mushroom conches are good indicators of internal tree rot.
BY Beau Brodbeck, Ph.D., Community Forestry and Arboriculture Extension Specialist, Auburn University / mobilecountymastergardeners.org
An unfortunate but common scenario that repeats itself over and over again goes something like this: A homeowner buys a house surrounded by tall trees only to learn that many are in poor health, requiring costly maintenance or removal. There are two issues here that can be particularly troublesome. First, the cost of unscheduled tree maintenance, and second, the loss of trees that provide shade, beauty, and higher land values. In some cases, people 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, assess the health of the tree. Tree health is a good indicator of past construction damage or trees reaching the end of their functional life. A tree’s foliage and canopy are the best indicators of its overall health. A healthy tree will have dense, dark green foliage that is evenly distributed around the canopy. Early signs of tree dieback will include foliage that turns yellow and becomes sparse. Foliage can also become patchy or patchy, with leaves clustered in one area and wide gaps in others. These signs can be subtle and highly variable, so it is useful to find trees of the same species and size to use for comparison.
A more obvious and problematic symptom of progressive tree dieback is the presence of dead branches at the top or outer margin of the canopy. Ignore dead limbs inside or on the lower parts of the canopy. These are naturally lost due to shade from the tree’s growth or surrounding vegetation. However, dead branch tips, especially when large branches die, signal that the tree is dying. It is important to note that depending on the tree species, its age and the damage caused, this dieback process can progress quickly (one to three years) or over a decade or more. With early intervention, it may be possible to reverse tree decline using proper tree maintenance techniques, which could be costly. If the top quarter or more of the tree is dead, removal is inevitable.
Second, assess trees near the house for faults that could increase the risk of failure. Buying 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 the roots have been cut into the drip line of the tree, the future health of the tree and possibly its stability are issues. Other construction-related issues include soil compaction caused by driving or storing materials in the tree’s drip line or burying roots with grade changes. Note that newly installed sod and landscaping can mask many of these issues.
Assessing tree health is a good method to determine if there has been any construction-related root damage. However, be aware that some trees may only show subtle signs the first year, becoming more obvious over time. Therefore, you should carefully inspect the trees and learn about past building practices.
There are other shaft defects, not related to construction, to look for as well. These include:
- Lightning scars; look for missing strips of bark along the length of the tree
- Cracks; look for deep cracks in the wood, especially in the crotches of forked trees
- Rot; signs of internal rot include fungal fruiting bodies (conches and mushrooms). missing bark, oozing wounds and carpenter ants
- Large cavities; cavities extending more than a third of the shaft diameter can be problematic
- Sawdust; borers in trees will leave fine sawdust on the bark and base of the tree
Finally, get a second opinion. Assessing tree health, and particularly tree risk, can be a complex and highly subjective process, based on the knowledge and experience of the assessor. If in doubt, consider hiring an arborist certified by the International Society of Arboriculture who is qualified in tree risk assessment to assess the health and risk potential of the tree. A few hundred dollars up front could save you thousands of dollars and, more importantly, the heartache of having to remove trees you were hoping to profit from. This knowledge can help you decide if trees are going to be a valuable part of your landscape for years to come or a potential liability. Finally, this information can be useful when negotiating the sale price of the house.
For a more detailed guide to tree risk assessment, see: 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, visit treesaregood.org.
Garden opportunities for your calendar:
What: Gulf Coast Camellia Society Annual Conference
Where: Mobile Botanical Gardens and Bellingrath Gardens and Home
When: October 21-22
Speakers include: Maarten van der Giessen, Bobby Green, Kip McConnell, Mark Crawford, Forrest Latta, Seth Allen, Robin Krchak and Dr. Todd Lasseigne
Fees: $125 for both days or $60 for Friday, $80 for Saturday
Membership required: single $10/year or couple $12/year
To register: mobilebotanicalgardens.org/2022-gulf-coast-camellia-society-conference
Registration deadline: October 3
What: Visit the Mobile Botanical Gardens
Where: 5151 Museum Drive, Mobile
When: Wednesday to Sunday (check website for times and prices)
Lunch: Book on Wednesdays and Fridays
More information: MobileBotanicalGardens.org
What: Visit Bellingrath Gardens
Where: 12401 Bellingrath Gardens Road, Theodore
When: 8 a.m. to 5 p.m. daily
More information: bellingrath.org
What: Enjoy the mobile Japanese garden
Where: 700 Forest Hill Drive, Mobile
When: Every day during the day
Price: Free, but donations requested
More information: MobileJapaneseGarden.com
Master Gardener Helpline: 877-252-4769