Common Tree Diseases

The natural beauty of a tree can often be spoiled by tree diseases. These diseases can be killing your trees from the inside out, whether it is a result of fungi, other plants, or insects.  

If you want to help protect your trees and know when to call a tree service Arlington, here are ways to spot the most common tree diseases.  

Bark Beetles 

Bark beetles are extremely tiny and are grayish or brownish in color. Typically, they feed on branches that are weakened or damaged. If you find tunnels or pinholes that run perpendicular to the tree’s grain, that’s a sign of bark beetles. 

Redheaded Ash Borer 

The redheaded ash borer creates a hole that is a bit oval. They usually start by feeding on the exterior sapwood. However, they can tunnel eventually across the tree’s trunk. 

Ash Borer or Lilac Borer 

The lilac/ash borer is the most popular wood borer. You can typically find them in Ash trees. The larvae primarily feed in the Ash tree’s lower trunk. But, they might tunnel into the lower areas.  

Root Collar Rot 

For those who don’t know, a tree can be quickly killed by a root collar rot. This is particularly true for honeylocust trees. That’s why you have to look for the signs and treat your tree immediately.  

The tree might already have a lot of damage if fall colors prematurely appear. In addition to that, you should look for tiny drops of gum on the stem. 

It might be the start of collar rot if you can remove a piece of loose bark and see discolored wood.  


In general, cankers are caused by fungi. Keeping your tree healthy is the ideal method to prevent cankers. You should maintain them during times of stress, such as drought. In addition to that, you have to avoid causing stress or wounding your trees.  

You should search for leaves prematurely falling, yellow foliage, lack of foliage, and dead branches. Typically, you can find cankers at the tree’s base.  

Cankers usually look like hollows with rough and huge ridges. You can also search for loose bark that has a yellow or red discoloration. 

Armillaria Root Disease 

A fungus that spreads across the roots of a tree is called Armillaria. They are usually common in Pinyon Pines. It can feed on dead wood for many years. This disease has a tendency to attack stressed trees. 

To spot this disease, you can look for a thin crown at the tree’s top portion. You might also find stringy, yellow rot at the tree’s base, mushrooms, or resin. 

Dwarf Mistletoe 

One plant that can take over a tree is dwarf mistletoe. This plant can kill your tree. This plant is a flowering and leafless plant that steals the water and nutrients of the tree by gradually covering the branches of the tree.  

Dwarf mistletoe has shoots that are brownish-green or yellowish-green. Usually, these shoots protrude from the branches of the tree.  

You will see a bark swelling at the infected area if dwarf mistletoe is killing your tree.