By itself, tree decay can be a major concern, especially if found in a soft-wooded tree species such as silver maple or poplar. Fortunately, some species are quite resistant and if other stressors aren’t present in a significant capacity, it may not be as worrisome as other problems such as poor location, planting errors, overfertilization or drought. A step-by-step approach works best when inspecting trees for decay:
- Use your eyes. Look for rot pockets, oozing, weeping, conks and different colors on the bark and branches.
- Walk the property extensively and identify possible targets. Interview the property owner and neighbors to get a handle on the frequency of use on the site.
- Use your experience. Certain tree species in certain locations are likely to develop decay. Locate tree parts that could fall on a target.
- Look closer using probing tools: golf club, rebar or irrigation flag. Use a rubber mallet or the butt of a hatchet to tap the tree trunk where you suspect decay is present.
- If necessary, use invasive tools such as a resistograph or core sampler. Reserve these for important tree specimens. For example, inspecting an oak at the entrance to the “Harvard Oaks” subdivision or a memorial tree. If the property owner has plenty of money to spend on inspection, consider the use of a sonic tomograph, a device that can illustrate the inside of the tree without cutting into it.
- Consider the potential for each tree defect to cause failure in conjunction with the proximity of an important target.
- Put it all together in the form of a relative hazard assessment, combining the presence and extent of the decay with other defects.
Editor’s note: These steps were taken from an article by John Fech in the November 2012 issue of Tree Services.