Unfortunately, when undetected and unmanaged, tree diseases can spread throughout a community and have devastating impacts on local wildlife. However, many tree diseases can be reversed and mitigated when correctly identified.

But what are the signs of disease and trees, and how do arborists identify them?

In this blog post, Arboraxepert’s tree experts discuss some of the most common tree diseases and explain the process arborists use to diagnose and resolve issues. We highlight some signs to watch out for in your trees and clarify the problems that commonly harm them.

What Are the Most Common Tree Diseases?

Before exploring the ways that arborists identify tree diseases, it’s worthwhile to briefly explain some of the most common tree diseases that impact residential and commercial properties. While tree diseases vary from region to region and can be exacerbated by climate conditions, there are a handful of diseases that regularly plague trees and should be watched out for.

Here are some common diseases that are found in urban and forest environments:

  • Emerald ash borer: This is a type of beetle that’s been a major threat to ash trees and can cause widespread destruction if not removed promptly.
  • Dutch elm disease: This is a fungal disease that affects elm trees and can swiftly deteriorate the health and structural integrity of trees.
  • Beech bark disease: This is a fungal disease that affects beech trees and kills their bark.
  • Apple scab: This is a fungal disease that affects fruit trees. It results in twisted leaves and brown spots on fruit, compromising their integrity.
  • Anthracnose: This is a fungal disease that affects hardwood trees, causing dead areas on the branches and blotches on leaves.
  • Powdery mildew: This is a fungal infection that manifests through small white spores on the edges of leaves, damaging the growth of trees.
  • Cankers: These are bacterial pathogens that manifest as lesions on a tree’s trunk and branches.

Common Signs of Tree Diseases to Watch Out For

While arborists are trained to spot indicators of distress, there are several common signs of tree diseases that you can look out for if you’re concerned about your property’s health. Pest infestations can be obvious to spot, as there are often holes in the bark or sawdust at the base of the tree. Severe leaning and changes should also alert you to internal issues.

If you notice any of the following, you may want to consult an arborist:

  • Leaf discoloration/spotting
  • Premature/unseasonal leaf drop and wilting
  • Cankers
  • Unusual growths or galls on branches
  • Peeling/cracked bark
  • Branch dieback
  • Canopy thinning

How Arborists Identify Weaknesses and Issues in Trees

To preserve tree health and environmental safety, arborists use a multi-faceted approach to identify weaknesses in trees. We often rely on visual inspections in conjunction with advanced testing and diagnostics to verify that there aren’t unusual growth patterns, soil issues, or nutrient deficiencies.

Arborists examine the tree's entire context, including local environmental conditions, typical growth for that type of species, and changes in the landscape that may impact its health.

Here are some common steps arborists follow when identifying issues in trees:

Visual Inspections: The Foundation of Tree Health Evaluations

Visual inspection is the cornerstone of arborists' diagnostic process and an essential first step when evaluating tree health. From looking at root flare for signs of decay to cankers or cracks on the trunk, irregularities are noted and measured for their severity. Things like bark condition, branch structure and attachment, leaf color, size, distribution, and sticky residues can all signify internal issues.

Visual clues form the basis for further testing and action.

Soil Analysis

Another key diagnostic is testing soil, as unusual pH, nutrient, and organic matter levels can impact the growth and longevity of your trees. Tree vitality and structure are inextricably linked to their root conditions, so testing soil level is crucial for understanding why symptoms emerge.

For instance, pH levels impact a tree’s ability to effectively absorb nutrients, while soil compaction can restrict root growth and reduce water penetration, leading to stress in your trees. In urban environments, contaminants like road salt and pollutants from surrounding areas can also harm the tree.

Additionally, testing soil samples can reveal the presence of pathogens or nematodes that may attack the root system. The information from analyzing soil conditions allows arborists to develop targeted treatment plans and address the root cause of issues rather than just treating visible symptoms.

Bark Evaluation

Bark evaluation is another critical aspect of tree health diagnostics, as the tree’s outer layer serves as a litmus test for its overall health and internal issues. Evaluating the bark can also alert arborists to the presence of unwanted pests, as small holes, frass, and oozing sap can suggest infestations. Minor changes in bark texture and thickness provide essential clues about the tree’s growth patterns and development.

Leaf Assessment

Finally, assessing individual leaves can offer valuable insights into a tree’s health and catch potential issues. When foliage changes color prematurely, it can be the result of browning or scorching, which indicates drought stress and potential chemical damage.

Spots, blotches, and mottling are all indicative of diseases. While localized issues in branches can impact leaves, many systemic and environmental problems also manifest through things like leaf drop and wilting. Evaluating leaf characteristics allows arborists to flag issues early on and intervene swiftly to prevent further damage.

Arborists Can Help Support Healthy Tree Growth

Through tree health assessments, targeted treatments, and swift intervention, arborists can support healthy tree growth and create ideal conditions. Trees are extremely complicated organisms that are deeply entwined with surrounding plant and animal life. Partnering with a reputable arborist ensures your trees receive the care and treatment they need to thrive.

Connect With A Local Tree Expert Today

If you’re concerned about trees on your property, consider connecting with the team at Arboraxepert. Trees are our passion, and we’ve developed our expertise through years of local service. With the right equipment and information, you can help your property thrive and ensure your trees remain healthy and stable.

Schedule a consultation with us today by calling (613) 424-7331.