Cut Out Canker Disease With Proper Pruning

Posted on: 18 May 2015

Canker disease can cause tree decline, but in most cases it begins as localized areas of disease affecting single tree branches. The fungi that cause canker disease may be due to environmental stresses or a pathogen, depending on the host. You can keep a watchful eye for canker disease in your trees and prune out affected branches before more serious tree health problems set in. Canker diseases affecting the main trunk are difficult to manage, but disease affecting limbs are easy to cut off.

What Causes The Disease?

Canker disease is a fungus. Trees can become prone to canker disease for a variety of reasons:

  • Frost damage
  • Sun scald
  • Wounds
  • Drought stress

Dozens of species of fungi cause canker disease.

What Does It Look Like?

What you need to watch for are blisters on tree bark or necrotic areas on tree limbs. Areas of canker are often oval-shaped, but the size and shape can vary and are often reddish-brown in color. You may notice a split form between the bark and the affected tree tissue. The inner bark may turn black and give off an unpleasant odor. 

How Is It Controlled?

Canker disease is easier to control if it is caught early. Lesions that form on branches are trimmed off to prevent the fungus from spreading, affecting other parts of the tree. Large cankers on a tree's main trunk are difficult to control. You will most likely need to replace the tree. 

What Damage Does It Do?

Canker disease can kill affected branches, and if it spreads, it can weaken a tree structurally. A weakened limb or tree is at a greater risk of breaking off or toppling over in a wind or ice storm.

How Is It Prevented?

Canker disease can be prevented. Because the various fungi that cause canker disease most often affect trees that have wounds or are under some type of stress, keeping trees healthy is important. Here are some tips to keep trees healthy:

  • Plant trees in a location with well-draining soil and good air circulation to prevent fungi
  • Water trees deeply on a set schedule or use a drip irrigation system 
  • Keep weeds under control
  • Fertilize trees as needed to promote healthy growth

When your trees are vigorous and healthy, they also stand a better chance of fighting off cankers if they develop. 

If you think your tree has canker disease, you can call your local tree trimming service, like Tree Smart Inc, to come out and prune off the diseased branches. Tree professionals can also assist you in keeping your trees healthy. 


identifying issues with your trees

Do you know how to identify a sick or troublesome tree? Are there trees that hang over your home? Do you have trees that aren't quite as beautiful as they once were? I have created my blog to help as many people as possible identify and resolve problems with trees. Whether your tree is sick and needs attention, or if the tree is hanging over your home, causing roofing problems, you can learn a lot about what course of action to take by visiting my blog. Hopefully, you can find all of the information you need to save your trees and know when it is time to take them down.