How Do Arborists Diagnose A Tree?

If your tree is not looking healthy, it is a good idea to call an arborist or tree care professional. In most cases, they'll start by sending someone out to diagnose the tree and figure out exactly what's wrong with it. But how do arborists go about diagnosing a tree? Here are some of the key steps they'll take and tests they'll perform.


The first thing the arborist will do is simply look at the tree. They'll examine the trunk and any exposed roots for signs of canker or rot, which could indicate a root rot disease. They'll also look for any holes in the bark that might suggest an insect infestation is at play. Your arborist may even climb a ladder to go higher in the tree and take a look at any leaves that are starting to yellow or develop spots.

All of these observations can tell an arborist a lot about a tree and what's affecting it. Certain diseases cause different types of spots on the leaves, and even if you can't tell the difference, an arborist often can. They may, for example, be able to tell whether your tree has anthracnose or powdery mildew disease just by looking at the shape and color of the leaf spots.

Bacterial Sampling

Many tree diseases are caused by fungi, but there are times when bacteria are to blame. If your arborist thinks your tree may be affected by bacteria, they will likely take a swab of the tissue and then take that swab back to a lab in order to analyze the bacteria present. This will tell them exactly what kind of bacteria is causing the infection, which will ensure they recommend the right medications for treatment.

Soil Sampling

Sometimes, you may think the tree looks infected and diseased, when really the problem is a shortage or excess of certain nutrients in the soil. An overabundance of iron, for instance, can cause some trees' leaves to turn yellow. As such, an arborist may take a sample of your soil as a part of the diagnostic process. If they detect a deficiency in a certain nutrient, they may recommend a specific fertilizer for you to use. If there's an excess of a certain nutrient, you may be able to add a different nutrient to balance things out.

If you call an arborist and have them come to diagnose your tree, there's a good chance they'll use one or more of the methods above.

Contact an arborist to learn more about tree diagnosis