Written by: Fred Hoppe, Board Certified Master Arborist WI-0556B, Certified Tree Care Safety Professional 00036, and ISA Qualified Tree Risk Assessor
Frequently by the time urban trees show signs of stress or decay, the issue has progressed to stages where mitigation efforts may be too late. Annual inspections by a certified arborist can be instrumental in identifying these issues before they cause serious and irreversible damage. Similar to a doctor’s annual checkup, annual inspections are vital to maintaining beautiful, healthy trees that are an assist to the property and not a liability.
When assessing trees on a property, there are two main conditions to consider, tree health and structural stability/risk. These two conditions should not be confused and do not always correlate. It is important to have an understanding of both for a thorough assessment of your trees.
Tree Health
Inspecting a tree for health requires familiarity with the characteristics of the plant being assessed. Having a knowledge of typical species behaviors in our region is important, since many species have characteristics that are unique to specific regions.
Symptoms of a plant in poor health can include: leaf discoloration, abnormal leaf size, and/or dieback. Local biotic and abiotic disorders need to be known in order to be identified. The seriousness of a symptom and its effect on a plant's health can only be determined when the problem is identified correctly. In some instances, multiple inspections may be required throughout the growing season depending on species susceptibility to certain disease or insect pests.
Tree Structural Stability/Risk
Many home owners and property managers don’t realize that part of their legal duty to maintain their property in a safe, hazard-free condition includes their trees. A properly and regularly performed inspection of trees and implementation of a maintenance program can reduce hazardous conditions, preserve the property's value, and lessen the property owner’s exposure to expensive negligence lawsuits.
It is hard to imagine a home, municipality, community park, school campus or a construction project that doesn’t include trees, shrubs and other plants. Although trees add great value to the landscapes around us, if they are not monitored and cared for properly, they can become a legal liability. To the untrained home owner or manager, a tree may appear to be fine. Yet, many trees have suffered damage from lightning, wind, construction activity, insects, and disease. It is not uncommon for a healthy-looking, vigorously-growing tree to be a dangerous tree, one waiting for the right combination of wind, rain, ice or other circumstance to fail and cause a tragedy. Many states have recognized that property owners have an expressed duty to inspect and maintain their trees. A property owner may be considered negligent if he or she has a tree that falls and harms a person or damages property.
Required inspection can be performed by anyone. However, there are many problems difficult to detect by a home owner or manager. Property owners and professionals should work with a certified arborist to develop an annual inspection and maintenance plan for the trees that will alert the property owner to structurally unstable trees and provide a reasonable maintenance program.
So what should property owners and professionals property managers do? The following steps will help manage health and/or risk from your trees:
1. Develop a tree inspection and management policy.
2. Put the plan in writing and document efforts to alleviate known hazards.
3. Work with a certified arborist. This professional should be trained in visual tree assessment and hazard tree recognition, and be a member of one or more of the national arboricultural associations.